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  • wrapping boost::ublas with swig

    - by leon
    I am trying to pass data around the numpy and boost::ublas layers. I have written an ultra thin wrapper because swig cannot parse ublas' header correctly. The code is shown below #include <boost/numeric/ublas/vector.hpp> #include <boost/numeric/ublas/matrix.hpp> #include <boost/lexical_cast.hpp> #include <algorithm> #include <sstream> #include <string> using std::copy; using namespace boost; typedef boost::numeric::ublas::matrix<double> dm; typedef boost::numeric::ublas::vector<double> dv; class dvector : public dv{ public: dvector(const int rhs):dv(rhs){;}; dvector(); dvector(const int size, double* ptr):dv(size){ copy(ptr, ptr+sizeof(double)*size, &(dv::data()[0])); } ~dvector(){} }; with the SWIG interface that looks something like %apply(int DIM1, double* INPLACE_ARRAY1) {(const int size, double* ptr)} class dvector{ public: dvector(const int rhs); dvector(); dvector(const int size, double* ptr); %newobject toString; char* toString(); ~dvector(); }; I have compiled them successfully via gcc 4.3 and vc++9.0. However when I simply run a = dvector(array([1.,2.,3.])) it gives me a segfault. This is the first time I use swigh with numpy and not have fully understanding between the data conversion and memory buffer passing. Does anyone see something obvious I have missed? I have tried to trace through with a debugger but it crashed within the assmeblys of python.exe. I have no clue if this is a swig problem or of my simple wrapper. Anything is appreciated.

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  • G++, compiler warnings, c++ templates

    - by Ian
    During the compilatiion of the C++ program those warnings appeared: c:/MinGW/bin/../lib/gcc/mingw32/3.4.5/../../../../include/c++/3.4.5/bc:/MinGW/bin/../lib/gcc/mingw32/3.4.5/../../../../include/c++/3.4.5/bits/stl_algo.h:2317: instantiated from `void std::partial_sort(_RandomAccessIterator, _RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator<Object<double>**, std::vector<Object<double>*, std::allocator<Object<double>*> > >, _Compare = sortObjects<double>]' c:/MinGW/bin/../lib/gcc/mingw32/3.4.5/../../../../include/c++/3.4.5/bits/stl_algo.h:2506: instantiated from `void std::__introsort_loop(_RandomAccessIterator, _RandomAccessIterator, _Size, _Compare) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator<Object<double>**, std::vector<Object<double>*, std::allocator<Object<double>*> > >, _Size = int, _Compare = sortObjects<double>]' c:/MinGW/bin/../lib/gcc/mingw32/3.4.5/../../../../include/c++/3.4.5/bits/stl_algo.h:2589: instantiated from `void std::sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator<Object<double>**, std::vector<Object<double>*, std::allocator<Object<double>*> > >, _Compare = sortObjects<double>]' io/../structures/objects/../../algorithm/analysis/../../structures/list/ObjectsList.hpp:141: instantiated from `void ObjectsList <T>::sortObjects(unsigned int, T, T, T, T, unsigned int) [with T = double]' I do not why, because all objects have only template parameter T, their local variables are also T. The only place, where I am using double is main. There are objects of type double creating and adding into the ObjectsList... Object <double> o1; ObjectsList <double> olist; olist.push_back(o1); .... T xmin = ..., ymin = ..., xmax = ..., ymax = ...; unsigned int n = ...; olist.sortAllObjects(xmin, ymin, xmax, ymax, n); and comparator template <class T> class sortObjects { private: unsigned int n; T xmin, ymin, xmax, ymax; public: sortObjects ( const T xmin_, const T ymin_, const T xmax_, const T ymax_, const int n_ ) : xmin ( xmin_ ), ymin ( ymin_ ), xmax ( xmax_ ), ymax ( ymax_ ), n ( n_ ) {} bool operator() ( const Object <T> *o1, const Object <T> *o2 ) const { T dmax = (std::max) ( xmax - xmin, ymax - ymin ); T x_max = ( xmax - xmin ) / dmax; T y_max = ( ymax - ymin ) / dmax; ... return ....; } representing ObjectsList method: template <class T> void ObjectsList <T> ::sortAllObjects ( const T xmin, const T ymin, const T xmax, const T ymax, const unsigned int n ) { std::sort ( objects.begin(), objects.end(), sortObjects <T> ( xmin, ymin, xmax, ymax, n ) ); }

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  • Python dictionary key missing

    - by Greg K
    I thought I'd put together a quick script to consolidate the CSS rules I have distributed across multiple CSS files, then I can minify it. I'm new to Python but figured this would be a good exercise to try a new language. My main loop isn't parsing the CSS as I thought it would. I populate a list with selectors parsed from the CSS files to return the CSS rules in order. Later in the script, the list contains an element that is not found in the dictionary. for line in self.file.readlines(): if self.hasSelector(line): selector = self.getSelector(line) if selector not in self.order: self.order.append(selector) elif selector and self.hasProperty(line): # rules.setdefault(selector,[]).append(self.getProperty(line)) property = self.getProperty(line) properties = [] if selector not in rules else rules[selector] if property not in properties: properties.append(property) rules[selector] = properties # print "%s :: %s" % (selector, "".join(rules[selector])) return rules Error encountered: $ css-combine combined.css test1.css test2.css Traceback (most recent call last): File "css-combine", line 108, in <module> c.run(outfile, stylesheets) File "css-combine", line 64, in run [(selector, rules[selector]) for selector in parser.order], KeyError: 'p' Swap the inputs: $ css-combine combined.css test2.css test1.css Traceback (most recent call last): File "css-combine", line 108, in <module> c.run(outfile, stylesheets) File "css-combine", line 64, in run [(selector, rules[selector]) for selector in parser.order], KeyError: '#header_.title' I've done some quirky things in the code like sub spaces for underscores in dictionary key names in case it was an issue - maybe this is a benign precaution? Depending on the order of the inputs, a different key cannot be found in the dictionary. The script: #!/usr/bin/env python import optparse import re class CssParser: def __init__(self): self.file = False self.order = [] # store rules assignment order def parse(self, rules = {}): if self.file == False: raise IOError("No file to parse") selector = False for line in self.file.readlines(): if self.hasSelector(line): selector = self.getSelector(line) if selector not in self.order: self.order.append(selector) elif selector and self.hasProperty(line): # rules.setdefault(selector,[]).append(self.getProperty(line)) property = self.getProperty(line) properties = [] if selector not in rules else rules[selector] if property not in properties: properties.append(property) rules[selector] = properties # print "%s :: %s" % (selector, "".join(rules[selector])) return rules def hasSelector(self, line): return True if re.search("^([#a-z,\.:\s]+){", line) else False def getSelector(self, line): s = re.search("^([#a-z,:\.\s]+){", line).group(1) return "_".join(s.strip().split()) def hasProperty(self, line): return True if re.search("^\s?[a-z-]+:[^;]+;", line) else False def getProperty(self, line): return re.search("([a-z-]+:[^;]+;)", line).group(1) class Consolidator: """Class to consolidate CSS rule attributes""" def run(self, outfile, files): parser = CssParser() rules = {} for file in files: try: parser.file = open(file) rules = parser.parse(rules) except IOError: print "Cannot read file: " + file finally: parser.file.close() self.serialize( [(selector, rules[selector]) for selector in parser.order], outfile ) def serialize(self, rules, outfile): try: f = open(outfile, "w") for rule in rules: f.write( "%s {\n\t%s\n}\n\n" % ( " ".join(rule[0].split("_")), "\n\t".join(rule[1]) ) ) except IOError: print "Cannot write output to: " + outfile finally: f.close() def init(): op = optparse.OptionParser( usage="Usage: %prog [options] <output file> <stylesheet1> " + "<stylesheet2> ... <stylesheetN>", description="Combine CSS rules spread across multiple " + "stylesheets into a single file" ) opts, args = op.parse_args() if len(args) < 3: if len(args) == 1: print "Error: No input files specified.\n" elif len(args) == 2: print "Error: One input file specified, nothing to combine.\n" op.print_help(); exit(-1) return [opts, args] if __name__ == '__main__': opts, args = init() outfile, stylesheets = [args[0], args[1:]] c = Consolidator() c.run(outfile, stylesheets) Test CSS file 1: body { background-color: #e7e7e7; } p { margin: 1em 0em; } File 2: body { font-size: 16px; } #header .title { font-family: Tahoma, Geneva, sans-serif; font-size: 1.9em; } #header .title a, #header .title a:hover { color: #f5f5f5; border-bottom: none; text-shadow: 2px 2px 3px rgba(0, 0, 0, 1); } Thanks in advance.

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  • Unable to verify body hash for DKIM

    - by Joshua
    I'm writing a C# DKIM validator and have come across a problem that I cannot solve. Right now I am working on calculating the body hash, as described in Section 3.7 Computing the Message Hashes. I am working with emails that I have dumped using a modified version of EdgeTransportAsyncLogging sample in the Exchange 2010 Transport Agent SDK. Instead of converting the emails when saving, it just opens a file based on the MessageID and dumps the raw data to disk. I am able to successfully compute the body hash of the sample email provided in Section A.2 using the following code: SHA256Managed hasher = new SHA256Managed(); ASCIIEncoding asciiEncoding = new ASCIIEncoding(); string rawFullMessage = File.ReadAllText(@"C:\Repositories\Sample-A.2.txt"); string headerDelimiter = "\r\n\r\n"; int headerEnd = rawFullMessage.IndexOf(headerDelimiter); string header = rawFullMessage.Substring(0, headerEnd); string body = rawFullMessage.Substring(headerEnd + headerDelimiter.Length); byte[] bodyBytes = asciiEncoding.GetBytes(body); byte[] bodyHash = hasher.ComputeHash(bodyBytes); string bodyBase64 = Convert.ToBase64String(bodyHash); string expectedBase64 = "2jUSOH9NhtVGCQWNr9BrIAPreKQjO6Sn7XIkfJVOzv8="; Console.WriteLine("Expected hash: {1}{0}Computed hash: {2}{0}Are equal: {3}", Environment.NewLine, expectedBase64, bodyBase64, expectedBase64 == bodyBase64); The output from the above code is: Expected hash: 2jUSOH9NhtVGCQWNr9BrIAPreKQjO6Sn7XIkfJVOzv8= Computed hash: 2jUSOH9NhtVGCQWNr9BrIAPreKQjO6Sn7XIkfJVOzv8= Are equal: True Now, most emails come across with the c=relaxed/relaxed setting, which requires you to do some work on the body and header before hashing and verifying. And while I was working on it (failing to get it to work) I finally came across a message with c=simple/simple which means that you process the whole body as is minus any empty CRLF at the end of the body. (Really, the rules for Body Canonicalization are quite ... simple.) Here is the real DKIM email with a signature using the simple algorithm (with only unneeded headers cleaned up). Now, using the above code and updating the expectedBase64 hash I get the following results: Expected hash: VnGg12/s7xH3BraeN5LiiN+I2Ul/db5/jZYYgt4wEIw= Computed hash: ISNNtgnFZxmW6iuey/3Qql5u6nflKPTke4sMXWMxNUw= Are equal: False The expected hash is the value from the bh= field of the DKIM-Signature header. Now, the file used in the second test is a direct raw output from the Exchange 2010 Transport Agent. If so inclined, you can view the modified EdgeTransportLogging.txt. At this point, no matter how I modify the second email, changing the start position or number of CRLF at the end of the file I cannot get the files to match. What worries me is that I have been unable to validate any body hash so far (simple or relaxed) and that it may not be feasible to process DKIM through Exchange 2010.

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  • Using a type parameter and a pointer to the same type parameter in a function template

    - by Darel
    Hello, I've written a template function to determine the median of any vector or array of any type that can be sorted with sort. The function and a small test program are below: #include <algorithm> #include <vector> #include <iostream> using namespace::std; template <class T, class X> void median(T vec, size_t size, X& ret) { sort(vec, vec + size); size_t mid = size/2; ret = size % 2 == 0 ? (vec[mid] + vec[mid-1]) / 2 : vec[mid]; } int main() { vector<double> v; v.push_back(2); v.push_back(8); v.push_back(7); v.push_back(4); v.push_back(9); double a[5] = {2, 8, 7, 4, 9}; double r; median(v.begin(), v.size(), r); cout << r << endl; median(a, 5, r); cout << r << endl; return 0; } As you can see, the median function takes a pointer as an argument, T vec. Also in the argument list is a reference variable X ret, which is modified by the function to store the computed median value. However I don't find this a very elegant solution. T vec will always be a pointer to the same type as X ret. My initial attempts to write median had a header like this: template<class T> T median(T *vec, size_t size) { sort(vec, vec + size); size_t mid = size/2; return size % 2 == 0 ? (vec[mid] + vec[mid-1]) / 2 : vec[mid]; } I also tried: template<class T, class X> X median(T vec, size_t size) { sort(vec, vec + size); size_t mid = size/2; return size % 2 == 0 ? (vec[mid] + vec[mid-1]) / 2 : vec[mid]; } I couldn't get either of these to work. My question is, can anyone show me a working implementation of either of my alternatives? Thanks for looking!

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  • Going from a math career to a cs career: how to do it?

    - by Joseph
    Hey, I'm looking for some advice on how to successfully make the transition from mathematics to CS. My academic background is in mathematics (BS and MSc), and I've taken loads of math courses as well. You name it, and I took it: Measure Theory, Algebra, PDES, Manifolds, Complex Analysis, etc. I progressed quite far along this track, and at one point, I thought I would be a professional mathematician...But around the time I was finishing my MSc, I really got sick of it. Studying very abstract mathematics was fun, but it really lost it's appeal to me. Outside of a couple hundred people, I'm not sure if anybody would understand my research. I did not want to be 60 years old and say that my only contribution to the world consisted of published papers. Anyways, I've been an off and on hobbyist programmer since 2002. I've programmed in C and Java (just small projects), and I really started to be drawn to the area as time passed. There's a real appeal to CS work because, well, it actually means something to other people out there! I enjoy all parts of it: designing webpages (a real artistic appeal). On the other end, I do enjoy toying with compilers and more nitty-gritty stuff as well. Suffice to say, I have broad interests out there. Anyways, I know it's a bit late, but I was wondering if there were other folks out there who made the change, and if so, how I could do so. I know I have some fairly big gaps to fill in terms of data structures, lack of internship experience, etc. But I really would like to make this work. So my question is simply: How can I make the switch from math to CS? To pay the bills, I'll be doing financial analysis for a company, but I'd like to eventually transition into a developer type position. I've been reading "Algorithm Design" by Tardos and doing all the problems. It's not hard to make progress since the problems are far more concrete than the stuff I've been doing the past six years. I feel I can make fairly rapid progress in picking up all the materials from data structures, etc. but none of it can substitute the past several years I've lost. Anyways, I'm eager to learn but would love some advice/concrete direction. Thanks, Joseph

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  • Binary Search Help

    - by aloh
    Hi, for a project I need to implement a binary search. This binary search allows duplicates. I have to get all the index values that match my target. I've thought about doing it this way if a duplicate is found to be in the middle: Target = G Say there is this following sorted array: B, D, E, F, G, G, G, G, G, G, Q, R S, S, Z I get the mid which is 7. Since there are target matches on both sides, and I need all the target matches, I thought a good way to get all would be to check mid + 1 if it is the same value. If it is, keep moving mid to the right until it isn't. So, it would turn out like this: B, D, E, F, G, G, G, G, G, G (MID), Q, R S, S, Z Then I would count from 0 to mid to count up the target matches and store their indexes into an array and return it. That was how I was thinking of doing it if the mid was a match and the duplicate happened to be in the mid the first time and on both sides of the array. Now, what if it isn't a match the first time? For example: B, D, E, F, G, G, J, K, L, O, Q, R, S, S, Z Then as normal, it would grab the mid, then call binary search from first to mid-1. B, D, E, F, G, G, J Since G is greater than F, call binary search from mid+1 to last. G, G, J. The mid is a match. Since it is a match, search from mid+1 to last through a for loop and count up the number of matches and store the match indexes into an array and return. Is this a good way for the binary search to grab all duplicates? Please let me know if you see problems in my algorithm and hints/suggestions if any. The only problem I see is that if all the matches were my target, I would basically be searching the whole array but then again, if that were the case I still would need to get all the duplicates. Thank you BTW, my instructor said we cannot use Vectors, Hash or anything else. He wants us to stay on the array level and get used to using them and manipulating them.

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  • How do I refactor these two C# functions to abstrtact their logic from the specific class properties

    - by ObligatoryMoniker
    I have two functions whose underlying logic is the same but in one case it sets one property value on a class and in another case it sets a different one. How can I rewrite the following two functions to abstract away as much of the algorithm as possible so that I can make changes in logic in a single place? SetBillingAddress private void SetBillingAddress(OrderAddress newBillingAddress) { BasketHelper basketHelper = new BasketHelper(SiteConstants.BasketName); OrderAddress oldBillingAddress = basketHelper.Basket.Addresses[basketHelper.BillingAddressID]; bool NewBillingAddressIsNotOldBillingAddress = ((oldBillingAddress == null) || (newBillingAddress.OrderAddressId != oldBillingAddress.OrderAddressId)); bool BillingAddressHasBeenPreviouslySet = (oldBillingAddress != null); bool BillingAddressIsNotSameAsShippingAddress = (basketHelper.ShippingAddressID != basketHelper.BillingAddressID); bool NewBillingAddressIsNotShippingAddress = (newBillingAddress.OrderAddressId != basketHelper.ShippingAddressID); if (NewBillingAddressIsNotOldBillingAddress && BillingAddressHasBeenPreviouslySet && BillingAddressIsNotSameAsShippingAddress) { basketHelper.Basket.Addresses.Remove(oldBillingAddress); } if (NewBillingAddressIsNotOldBillingAddress && NewBillingAddressIsNotShippingAddress) { basketHelper.Basket.Addresses.Add(newBillingAddress); } basketHelper.BillingAddressID = newBillingAddress.OrderAddressId; basketHelper.Basket.Save(); } And here is the second one: SetShippingAddress private void SetBillingAddress(OrderAddress newShippingAddress) { BasketHelper basketHelper = new BasketHelper(SiteConstants.BasketName); OrderAddress oldShippingAddress = basketHelper.Basket.Addresses[basketHelper.ShippingAddressID]; bool NewShippingAddressIsNotOldShippingAddress = ((oldShippingAddress == null) || (newShippingAddress.OrderAddressId != oldShippingAddress.OrderAddressId)); bool ShippingAddressHasBeenPreviouslySet = (oldShippingAddress != null); bool ShippingAddressIsNotSameAsBillingAddress = (basketHelper.ShippingAddressID != basketHelper.BillingAddressID); bool NewShippingAddressIsNotBillingAddress = (newShippingAddress.OrderAddressId != basketHelper.BillingAddressID); if (NewShippingAddressIsNotOldShippingAddress && ShippingAddressHasBeenPreviouslySet && ShippingAddressIsNotSameAsBillingAddress) { basketHelper.Basket.Addresses.Remove(oldShippingAddress); } if (NewShippingAddressIsNotOldShippingAddress && NewShippingAddressIsNotBillingAddress) { basketHelper.Basket.Addresses.Add(newShippingAddress); } basketHelper.ShippingAddressID = newShippingAddress.OrderAddressId; basketHelper.Basket.Save(); } My initial thought was that if I could pass a class's property by refernce then I could rewrite the previous functions into something like private void SetPurchaseOrderAddress(OrderAddress newAddress, ref String CurrentChangingAddressIDProperty) and then call this function and pass in either basketHelper.BillingAddressID or basketHelper.ShippingAddressID as CurrentChangingAddressIDProperty but since I can't pass C# properties by reference I am not sure what to do with this code to be able to reuse the logic in both places. Thanks for any insight you can give me.

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  • Python/Biophysics- Trying to code a simple stochastic simulation!

    - by user359597
    Hey guys- I'm trying to figure out what to make of the following code- this is not the clear, intuitive python I've been learning. Was it written in C or something then wrapped in a python fxn? The code I wrote (not shown) is using the same math, but I couldn't figure out how to write a conditional loop. If anyone could explain/decipher/clean this up, I'd be really appreciative. I mean- is this 'good' python- or does it look funky? I'm brand new to this- but it's like the order of the fxns is messed up? I understand Gillespie's- I've successfully coded several simpler simulations. So in a nutshell- good code-(pythonic)? order? c? improvements? am i being an idiot? The code shown is the 'answer,' to the following question from a biophysics text (petri-net not shown and honestly not necessary to understand problem): "In a programming language of your choice, implement Gillespie’s First Reaction Algorithm to study the temporal behaviour of the reaction A---B in which the transition from A to B can only take place if another compound, C, is present, and where C dynamically interconverts with D, as modelled in the Petri-net below. Assume that there are 100 molecules of A, 1 of C, and no B or D present at the start of the reaction. Set kAB to 0.1 s-1 and both kCD and kDC to 1.0 s-1. Simulate the behaviour of the system over 100 s." def sim(): # Set the rate constants for all transitions kAB = 0.1 kCD = 1.0 kDC = 1.0 # Set up the initial state A = 100 B = 0 C = 1 D = 0 # Set the start and end times t = 0.0 tEnd = 100.0 print "Time\t", "Transition\t", "A\t", "B\t", "C\t", "D" # Compute the first interval transition, interval = transitionData(A, B, C, D, kAB, kCD, kDC) # Loop until the end time is exceded or no transition can fire any more while t <= tEnd and transition >= 0: print t, '\t', transition, '\t', A, '\t', B, '\t', C, '\t', D t += interval if transition == 0: A -= 1 B += 1 if transition == 1: C -= 1 D += 1 if transition == 2: C += 1 D -= 1 transition, interval = transitionData(A, B, C, D, kAB, kCD, kDC) def transitionData(A, B, C, D, kAB, kCD, kDC): """ Returns nTransition, the number of the firing transition (0: A->B, 1: C->D, 2: D->C), and interval, the interval between the time of the previous transition and that of the current one. """ RAB = kAB * A * C RCD = kCD * C RDC = kDC * D dt = [-1.0, -1.0, -1.0] if RAB > 0.0: dt[0] = -math.log(1.0 - random.random())/RAB if RCD > 0.0: dt[1] = -math.log(1.0 - random.random())/RCD if RDC > 0.0: dt[2] = -math.log(1.0 - random.random())/RDC interval = 1e36 transition = -1 for n in range(len(dt)): if dt[n] > 0.0 and dt[n] < interval: interval = dt[n] transition = n return transition, interval if __name__ == '__main__': sim()

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  • Find location using only distance and range?

    - by pinnacler
    Triangulation works by checking your angle to three KNOWN targets. "I know the that's the Lighthouse of Alexandria, it's located here (X,Y) on a map, and it's to my right at 90 degrees." Repeat 2 more times for different targets and angles. Trilateration works by checking your distance from three KNOWN targets. "I know the that's the Lighthouse of Alexandria, it's located here (X,Y) on a map, and I'm 100 meters away from that." Repeat 2 more times for different targets and ranges. But both of those methods rely on knowing WHAT you're looking at. Say you're in a forest and you can't differentiate between trees, but you know where key trees are. These trees have been hand picked as "landmarks." You have a robot moving through that forest slowly. Do you know of any ways to determine location based solely off of angle and range, exploiting geometry between landmarks? Note, you will see other trees as well, so you won't know which trees are key trees. Ignore the fact that a target may be occluded. Our pre-algorithm takes care of that. 1) If this exists, what's it called? I can't find anything. 2) What do you think the odds are of having two identical location 'hits?' I imagine it's fairly rare. 3) If there are two identical location 'hits,' how can I determine my exact location after I move the robot next. (I assume the chances of having 2 occurrences of EXACT angles in a row, after I reposition the robot, would be statistically impossible, barring a forest growing in rows like corn). Would I just calculate the position again and hope for the best? Or would I somehow incorporate my previous position estimate into my next guess? If this exists, I'd like to read about it, and if not, develop it as a side project. I just don't have time to reinvent the wheel right now, nor have the time to implement this from scratch. So if it doesn't exist, I'll have to figure out another way to localize the robot since that's not the aim of this research, if it does, lets hope it's semi-easy.

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  • I don't understand how work call_once

    - by SABROG
    Please help me understand how work call_once Here is thread-safe code. I don't understand why this need Thread Local Storage and global_epoch variables. Variable _fast_pthread_once_per_thread_epoch can be changed to constant/enum like {FAST_PTHREAD_ONCE_INIT, BEING_INITIALIZED, FINISH_INITIALIZED}. Why needed count calls in global_epoch? I think this code can be rewriting with logc: if flag FINISH_INITIALIZED do nothing, else go to block with mutexes and this all. #ifndef FAST_PTHREAD_ONCE_H #define FAST_PTHREAD_ONCE_H #include #include typedef sig_atomic_t fast_pthread_once_t; #define FAST_PTHREAD_ONCE_INIT SIG_ATOMIC_MAX extern __thread fast_pthread_once_t _fast_pthread_once_per_thread_epoch; #ifdef __cplusplus extern "C" { #endif extern void fast_pthread_once( pthread_once_t *once, void (*func)(void) ); inline static void fast_pthread_once_inline( fast_pthread_once_t *once, void (*func)(void) ) { fast_pthread_once_t x = *once; /* unprotected access */ if ( x _fast_pthread_once_per_thread_epoch ) { fast_pthread_once( once, func ); } } #ifdef __cplusplus } #endif #endif FAST_PTHREAD_ONCE_H Source fast_pthread_once.c The source is written in C. The lines of the primary function are numbered for reference in the subsequent correctness argument. #include "fast_pthread_once.h" #include static pthread_mutex_t mu = PTHREAD_MUTEX_INITIALIZER; /* protects global_epoch and all fast_pthread_once_t writes */ static pthread_cond_t cv = PTHREAD_COND_INITIALIZER; /* signalled whenever a fast_pthread_once_t is finalized */ #define BEING_INITIALIZED (FAST_PTHREAD_ONCE_INIT - 1) static fast_pthread_once_t global_epoch = 0; /* under mu */ __thread fast_pthread_once_t _fast_pthread_once_per_thread_epoch; static void check( int x ) { if ( x == 0 ) abort(); } void fast_pthread_once( fast_pthread_once_t *once, void (*func)(void) ) { /*01*/ fast_pthread_once_t x = *once; /* unprotected access */ /*02*/ if ( x _fast_pthread_once_per_thread_epoch ) { /*03*/ check( pthread_mutex_lock(µ) == 0 ); /*04*/ if ( *once == FAST_PTHREAD_ONCE_INIT ) { /*05*/ *once = BEING_INITIALIZED; /*06*/ check( pthread_mutex_unlock(µ) == 0 ); /*07*/ (*func)(); /*08*/ check( pthread_mutex_lock(µ) == 0 ); /*09*/ global_epoch++; /*10*/ *once = global_epoch; /*11*/ check( pthread_cond_broadcast(&cv;) == 0 ); /*12*/ } else { /*13*/ while ( *once == BEING_INITIALIZED ) { /*14*/ check( pthread_cond_wait(&cv;, µ) == 0 ); /*15*/ } /*16*/ } /*17*/ _fast_pthread_once_per_thread_epoch = global_epoch; /*18*/ check (pthread_mutex_unlock(µ) == 0); } } This code from BOOST: #ifndef BOOST_THREAD_PTHREAD_ONCE_HPP #define BOOST_THREAD_PTHREAD_ONCE_HPP // once.hpp // // (C) Copyright 2007-8 Anthony Williams // // Distributed under the Boost Software License, Version 1.0. (See // accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt) #include #include #include #include "pthread_mutex_scoped_lock.hpp" #include #include #include namespace boost { struct once_flag { boost::uintmax_t epoch; }; namespace detail { BOOST_THREAD_DECL boost::uintmax_t& get_once_per_thread_epoch(); BOOST_THREAD_DECL extern boost::uintmax_t once_global_epoch; BOOST_THREAD_DECL extern pthread_mutex_t once_epoch_mutex; BOOST_THREAD_DECL extern pthread_cond_t once_epoch_cv; } #define BOOST_ONCE_INITIAL_FLAG_VALUE 0 #define BOOST_ONCE_INIT {BOOST_ONCE_INITIAL_FLAG_VALUE} // Based on Mike Burrows fast_pthread_once algorithm as described in // http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2444.html template void call_once(once_flag& flag,Function f) { static boost::uintmax_t const uninitialized_flag=BOOST_ONCE_INITIAL_FLAG_VALUE; static boost::uintmax_t const being_initialized=uninitialized_flag+1; boost::uintmax_t const epoch=flag.epoch; boost::uintmax_t& this_thread_epoch=detail::get_once_per_thread_epoch(); if(epoch #endif I right understand, boost don't use atomic operation, so code from boost not thread-safe?

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  • R glm standard error estimate differences to SAS PROC GENMOD

    - by Michelle
    I am converting a SAS PROC GENMOD example into R, using glm in R. The SAS code was: proc genmod data=data0 namelen=30; model boxcoxy=boxcoxxy ~ AGEGRP4 + AGEGRP5 + AGEGRP6 + AGEGRP7 + AGEGRP8 + RACE1 + RACE3 + WEEKEND + SEQ/dist=normal; FREQ REPLICATE_VAR; run; My R code is: parmsg2 <- glm(boxcoxxy ~ AGEGRP4 + AGEGRP5 + AGEGRP6 + AGEGRP7 + AGEGRP8 + RACE1 + RACE3 + WEEKEND + SEQ , data=data0, family=gaussian, weights = REPLICATE_VAR) When I use summary(parmsg2) I get the same coefficient estimates as in SAS, but my standard errors are wildly different. The summary output from SAS is: Name df Estimate StdErr LowerWaldCL UpperWaldCL ChiSq ProbChiSq Intercept 1 6.5007436 .00078884 6.4991975 6.5022897 67911982 0 agegrp4 1 .64607262 .00105425 .64400633 .64813891 375556.79 0 agegrp5 1 .4191395 .00089722 .41738099 .42089802 218233.76 0 agegrp6 1 -.22518765 .00083118 -.22681672 -.22355857 73401.113 0 agegrp7 1 -1.7445189 .00087569 -1.7462352 -1.7428026 3968762.2 0 agegrp8 1 -2.2908855 .00109766 -2.2930369 -2.2887342 4355849.4 0 race1 1 -.13454883 .00080672 -.13612997 -.13296769 27817.29 0 race3 1 -.20607036 .00070966 -.20746127 -.20467944 84319.131 0 weekend 1 .0327884 .00044731 .0319117 .03366511 5373.1931 0 seq2 1 -.47509583 .00047337 -.47602363 -.47416804 1007291.3 0 Scale 1 2.9328613 .00015586 2.9325559 2.9331668 -127 The summary output from R is: Coefficients: Estimate Std. Error t value Pr(>|t|) (Intercept) 6.50074 0.10354 62.785 < 2e-16 AGEGRP4 0.64607 0.13838 4.669 3.07e-06 AGEGRP5 0.41914 0.11776 3.559 0.000374 AGEGRP6 -0.22519 0.10910 -2.064 0.039031 AGEGRP7 -1.74452 0.11494 -15.178 < 2e-16 AGEGRP8 -2.29089 0.14407 -15.901 < 2e-16 RACE1 -0.13455 0.10589 -1.271 0.203865 RACE3 -0.20607 0.09315 -2.212 0.026967 WEEKEND 0.03279 0.05871 0.558 0.576535 SEQ -0.47510 0.06213 -7.646 2.25e-14 The importance of the difference in the standard errors is that the SAS coefficients are all statistically significant, but the RACE1 and WEEKEND coefficients in the R output are not. I have found a formula to calculate the Wald confidence intervals in R, but this is pointless given the difference in the standard errors, as I will not get the same results. Apparently SAS uses a ridge-stabilized Newton-Raphson algorithm for its estimates, which are ML. The information I read about the glm function in R is that the results should be equivalent to ML. What can I do to change my estimation procedure in R so that I get the equivalent coefficents and standard error estimates that were produced in SAS? To update, thanks to Spacedman's answer, I used weights because the data are from individuals in a dietary survey, and REPLICATE_VAR is a balanced repeated replication weight, that is an integer (and quite large, in the order of 1000s or 10000s). The website that describes the weight is here. I don't know why the FREQ rather than the WEIGHT command was used in SAS. I will now test by expanding the number of observations using REPLICATE_VAR and rerunning the analysis.

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  • Runge-Kutta Method with adaptive step

    - by infoholic_anonymous
    I am implementing Runge-Kutta method with adaptive step in matlab. I get different results as compared to matlab's own ode45 and my own implementation of Runge-Kutta method with fixed step. What am I doing wrong in my code? Is it possible? function [ result ] = rk4_modh( f, int, init, h, h_min ) % % f - function handle % int - interval - pair (x_min, x_max) % init - initial conditions - pair (y1(0),y2(0)) % h_min - lower limit for h (step length) % h - initial step length % x - independent variable ( for example time ) % y - dependent variable - vertical vector - in our case ( y1, y2 ) function [ k1, k2, k3, k4, ka, y ] = iteration( f, h, x, y ) % core functionality performed within loop k1 = h * f(x,y); k2 = h * f(x+h/2, y+k1/2); k3 = h * f(x+h/2, y+k2/2); k4 = h * f(x+h, y+k3); ka = (k1 + 2*k2 + 2*k3 + k4)/6; y = y + ka; end % constants % relative error eW = 1e-10; % absolute error eB = 1e-10; s = 0.9; b = 5; % initialization i = 1; x = int(1); y = init; while true hy = y; hx = x; %algorithm [ k1, k2, k3, k4, ka, y ] = iteration( f, h, x, y ); % error estimation for j=1:2 [ hk1, hk2, hk3, hk4, hka, hy ] = iteration( f, h/2, hx, hy ); hx = hx + h/2; end err(:,i) = abs(hy - y); % step adjustment e = abs( hy ) * eW + eB; a = min( e ./ err(:,i) )^(0.2); mul = a * s; if mul >= 1 % step length admitted keepH(i) = h; k(:,:,i) = [ k1, k2, k3, k4, ka ]; previous(i,:) = [ x+h, y' ]; %' i = i + 1; if floor( x + h + eB ) == int(2) break; else h = min( [mul*h, b*h, int(2)-x] ); x = x + keepH(i-1); end else % step length requires further adjustments h = mul * h; if ( h < h_min ) error('Computation with given precision impossible'); end end end result = struct( 'val', previous, 'k', k, 'err', err, 'h', keepH ); end The function in question is: function [ res ] = fun( x, y ) % res(1) = y(2) + y(1) * ( 0.9 - y(1)^2 - y(2)^2 ); res(2) = -y(1) + y(2) * ( 0.9 - y(1)^2 - y(2)^2 ); res = res'; %' end The call is: res = rk4( @fun, [0,20], [0.001; 0.001], 0.008 ); The resulting plot for x1 : The result of ode45( @fun, [0, 20], [0.001, 0.001] ) is:

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  • why is my 3n+1 problem solution wrong?

    - by nunos
    I have recently started reading "Programming Challenges" book by S. Skiena and believe or not I am kind of stuck in the very first problem. Here's a link to the problem: 3n+1 problem Here's my code: #include <iostream> #include <vector> #include <algorithm> using namespace std; unsigned long calc(unsigned long n); int main() { int i, j, a, b, m; vector<int> temp; while (true) { cin >> i >> j; if (cin.fail()) break; if (i < j) { a = i; b = j; } else { a = j; b = i; } temp.clear(); for (unsigned int k = a; k != b; k++) { temp.push_back(calc(k)); } m = *max_element(temp.begin(), temp.end()); cout << i << ' ' << j << ' ' << m << endl; } } unsigned long calc(unsigned long n) { unsigned long ret = 1; while (n != 1) { if (n % 2 == 0) n = n/2; else n = 3*n + 1; ret++; } return ret; } I know the code is inefficient and I should not be using vectors to store the data. Anyway, I still would like to know what it's wrong with this, since, for me, it makes perfect sense, even though I am getting WA (wrong answer at programming challenges judge and RE (Runtime Error) at UVa judge). Thanks.

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  • Find location using only distance and bearing?

    - by pinnacler
    Triangulation works by checking your angle to three KNOWN targets. "I know the that's the Lighthouse of Alexandria, it's located here (X,Y) on a map, and it's to my right at 90 degrees." Repeat 2 more times for different targets and angles. Trilateration works by checking your distance from three KNOWN targets. "I know the that's the Lighthouse of Alexandria, it's located here (X,Y) on a map, and I'm 100 meters away from that." Repeat 2 more times for different targets and ranges. But both of those methods rely on knowing WHAT you're looking at. Say you're in a forest and you can't differentiate between trees, but you know where key trees are. These trees have been hand picked as "landmarks." You have a robot moving through that forest slowly. Do you know of any ways to determine location based solely off of angle and range, exploiting geometry between landmarks? Note, you will see other trees as well, so you won't know which trees are key trees. Ignore the fact that a target may be occluded. Our pre-algorithm takes care of that. 1) If this exists, what's it called? I can't find anything. 2) What do you think the odds are of having two identical location 'hits?' I imagine it's fairly rare. 3) If there are two identical location 'hits,' how can I determine my exact location after I move the robot next. (I assume the chances of having 2 occurrences of EXACT angles in a row, after I reposition the robot, would be statistically impossible, barring a forest growing in rows like corn). Would I just calculate the position again and hope for the best? Or would I somehow incorporate my previous position estimate into my next guess? If this exists, I'd like to read about it, and if not, develop it as a side project. I just don't have time to reinvent the wheel right now, nor have the time to implement this from scratch. So if it doesn't exist, I'll have to figure out another way to localize the robot since that's not the aim of this research, if it does, lets hope it's semi-easy.

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  • Exception thrown while accessing HTML DataTable in backing bean

    - by Denzil
    Hi folks, I am building a simple application in JSF with the CrUD functionality. I am trying to implement edit functionality using the tomahawk component .I am unable to retrieve the selected row in my backing bean. Here's my JSP file snip: <t:dataTable id="data" binding="#{selectOneRowList.dataTable}" styleClass="scrollerTable" headerClass="standardTable_Header" footerClass="standardTable_Header" rowClasses="standardTable_Row1,standardTable_Row2" columnClasses="standardTable_Column,standardTable_ColumnCentered,standardTable_Column" var="car" value="#{selectOneRowList.list}" sortColumn="#{selectOneRowList.sortColumn}" sortAscending="#{selectOneRowList.sortAscending}" preserveDataModel="false" preserveSort="true" preserveRowStates="true" rows="10" > <h:column> <f:facet name="header"> <h:outputText value="Select"/> </f:facet> <t:selectOneRow groupName="selection" id="hugo" value="#{selectOneRowList.selectedRowIndex}" onchange="submit();" immediate="true" valueChangeListener="#{selectOneRowList.processRowSelection}"/> </h:column> <h:column> <f:facet name="header"> </f:facet> <h:outputText value="#{car.id}" /> </h:column> <h:column> <f:facet name="header"> <h:outputText value="Cars" /> </f:facet> <h:outputText value="#{car.type}" /> </h:column> <t:column sortable="true"> <f:facet name="header"> <h:outputText value="Color" /> </f:facet> <h:outputText value="#{car.color}" /> </t:column> </t:dataTable> Here's my backing bean SelectOneRowList.java : public void editCar(ActionEvent event) { System.out.println("Row number ## " + _selectedRowIndex.toString() + " selected!"); System.out.println("Datatable ::"+ dataTable); System.out.println("Row Count ::" + dataTable.getRowCount()); dataItem = (SimpleCar) getDataTable().getRowData(); //selectedCar = (SimpleCar) _list.get(Integer.parseInt(_selectedRowIndex.toString())); selectedCar = (SimpleCar) dataTable.getRowData(); System.out.println(dataTable.getRowData()); } My DTO{Data Transfer Object} which is SimpleCar.java contains the variables ID, type, color and their respective setters/getters. The dataItem variable is of type "SimpleCar". The dataTable is of type HTMLDataTable. I am able to get the the first 3 SOP's but the 4th SOP isn't printed. I receive the following exception on the server : javax.faces.el.EvaluationException: Exception while invoking expression #{selectOneRowList.editCar} org.apache.myfaces.el.MethodBindingImpl.invoke(MethodBindingImpl.java:156) javax.faces.component.UICommand.broadcast(UICommand.java:89) javax.faces.component.UIViewRoot._broadcastForPhase(UIViewRoot.java:97) javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:171) org.apache.myfaces.lifecycle.InvokeApplicationExecutor.execute(InvokeApplicationExecutor.java:32) org.apache.myfaces.lifecycle.LifecycleImpl.executePhase(LifecycleImpl.java:95) org.apache.myfaces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:70) javax.faces.webapp.FacesServlet.service(FacesServlet.java:139) org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:341) On click of the edit button the editCar method in my backing bean is invoked. I need to get the data of the selected row in my backing bean. Why is the exception occurring ? The above example is taken from the tomawhawk examples WAR distributed on the website. I have gone through many links including the ones on BalusC but none of them have helped. Regards,

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  • How to verify if the private key matches with the certificate..?

    - by surendhar_s
    I have the private key stored as .key file.. -----BEGIN RSA PRIVATE KEY----- MIICXAIBAAKBgQD5YBS6V3APdgqaWAkijIUHRK4KQ6eChSaRWaw9L/4u8o3T1s8J rUFHQhcIo5LPaQ4BrIuzHS8yzZf0m3viCTdZAiDn1ZjC2koquJ53rfDzqYxZFrId 7a4QYUCvM0gqx5nQ+lw1KoY/CDAoZN+sO7IJ4WkMg5XbgTWlSLBeBg0gMwIDAQAB AoGASKDKCKdUlLwtRFxldLF2QPKouYaQr7u1ytlSB5QFtIih89N5Avl5rJY7/SEe rdeL48LsAON8DpDAM9Zg0ykZ+/gsYI/C8b5Ch3QVgU9m50j9q8pVT04EOCYmsFi0 DBnwNBRLDESvm1p6NqKEc7zO9zjABgBvwL+loEVa1JFcp5ECQQD9/sekGTzzvKa5 SSVQOZmbwttPBjD44KRKi6LC7rQahM1PDqmCwPFgMVpRZL6dViBzYyWeWxN08Fuv p+sIwwLrAkEA+1f3VnSgIduzF9McMfZoNIkkZongcDAzjQ8sIHXwwTklkZcCqn69 qTVPmhyEDA/dJeAK3GhalcSqOFRFEC812QJAXStgQCmh2iaRYdYbAdqfJivMFqjG vgRpP48JHUhCeJfOV/mg5H2yDP8Nil3SLhSxwqHT4sq10Gd6umx2IrimEQJAFNA1 ACjKNeOOkhN+SzjfajJNHFyghEnJiw3NlqaNmEKWNNcvdlTmecObYuSnnqQVqRRD cfsGPU661c1MpslyCQJBAPqN0VXRMwfU29a3Ve0TF4Aiu1iq88aIPHsT3GKVURpO XNatMFINBW8ywN5euu8oYaeeKdrVSMW415a5+XEzEBY= -----END RSA PRIVATE KEY----- And i extracted public key from ssl certificate file.. Below is the code i tried to verify if private key matches with ssl certificate or not.. I used the modulus[i.e. private key get modulus==public key get modulus] to check if they are matching.. And this seems to hold only for RSAKEYS.. But i want to check for other keys as well.. Is there any other alternative to do the same..?? private static boolean verifySignature(File serverCertificateFile, File serverCertificateKey) { try { byte[] certificateBytes = FileUtils.readFileToByteArray(serverCertificateFile); //byte[] keyBytes = FileUtils.readFileToByteArray(serverCertificateKey); RandomAccessFile raf = new RandomAccessFile(serverCertificateKey, "r"); byte[] buf = new byte[(int) raf.length()]; raf.readFully(buf); raf.close(); PKCS8EncodedKeySpec kspec = new PKCS8EncodedKeySpec(buf); KeyFactory kf; try { kf = KeyFactory.getInstance("RSA"); RSAPrivateKey privKey = (RSAPrivateKey) kf.generatePrivate(kspec); CertificateFactory certFactory = CertificateFactory.getInstance("X.509"); InputStream in = new ByteArrayInputStream(certificateBytes); //Generate Certificate in X509 Format X509Certificate cert = (X509Certificate) certFactory.generateCertificate(in); RSAPublicKey publicKey = (RSAPublicKey) cert.getPublicKey(); in.close(); return privKey.getModulus() == publicKey.getModulus(); } catch (NoSuchAlgorithmException ex) { logger.log(Level.SEVERE, "Such algorithm is not found", ex); } catch (CertificateException ex) { logger.log(Level.SEVERE, "certificate exception", ex); } catch (InvalidKeySpecException ex) { Logger.getLogger(CertificateConversion.class.getName()).log(Level.SEVERE, null, ex); } } catch (IOException ex) { logger.log(Level.SEVERE, "Signature verification failed.. This could be because the file is in use", ex); } return false; } And the code isn't working either.. throws invalidkeyspec exception

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  • Parsing language for both binary and character files

    - by Thorsten S.
    The problem: You have some data and your program needs specified input. For example strings which are numbers. You are searching for a way to transform the original data in a format you need. And the problem is: The source can be anything. It can be XML, property lists, binary which contains the needed data deeply embedded in binary junk. And your output format may vary also: It can be number strings, float, doubles.... You don't want to program. You want routines which gives you commands capable to transform the data in a form you wish. Surely it contains regular expressions, but it is very good designed and it offers capabilities which are sometimes much more easier and more powerful. Something like a super-grep which you can access (!) as program routines, not only as tool. It allows: joining/grouping/merging of results inserting/deleting/finding/replacing write macros which allows to execute a command chain repeatedly meta-grouping (lists-tables-hypertables) Example (No, I am not looking for a solution to this, it is just an example): You want to read xml strings embedded in a binary file with variable length records. Your tool reads the record length and deletes the junk surrounding your text. Now it splits open the xml and extracts the strings. Being Indian number glyphs and containing decimal commas instead of decimal points, your tool transforms it into ASCII and replaces commas with points. Now the results must be stored into matrices of variable length....etc. etc. I am searching for a good language / language-design and if possible, an implementation. Which design do you like or even, if it does not fulfill the conditions, wouldn't you want to miss ? EDIT: The question is if a solution for the problem exists and if yes, which implementations are available. You DO NOT implement your own sorting algorithm if Quicksort, Mergesort and Heapsort is available. You DO NOT invent your own text parsing method if you have regular expressions. You DO NOT invent your own 3D language for graphics if OpenGL/Direct3D is available. There are existing solutions or at least papers describing the problem and giving suggestions. And there are people who may have worked and experienced such problems and who can give ideas and suggestions. The idea that this problem is totally new and I should work out and implement it myself without background knowledge seems for me, I must admit, totally off the mark.

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  • Can my loop be optimized any more? (C++)

    - by Sagekilla
    Below is one of my inner loops that's run several thousand times, with input sizes of 20 - 1000 or more. Is there anything I can do to help squeeze any more performance out of this? I'm not looking to move this code to something like using tree codes (Barnes-Hut), but towards optimizing the actual calculations happening inside, since the same calculations occur in the Barnes-Hut algorithm. Any help is appreciated! typedef double real; struct Particle { Vector pos, vel, acc, jerk; Vector oldPos, oldVel, oldAcc, oldJerk; real mass; }; class Vector { private: real vec[3]; public: // Operators defined here }; real Gravity::interact(Particle *p, size_t numParticles) { PROFILE_FUNC(); real tau_q = 1e300; for (size_t i = 0; i < numParticles; i++) { p[i].jerk = 0; p[i].acc = 0; } for (size_t i = 0; i < numParticles; i++) { for (size_t j = i+1; j < numParticles; j++) { Vector r = p[j].pos - p[i].pos; Vector v = p[j].vel - p[i].vel; real r2 = lengthsq(r); real v2 = lengthsq(v); // Calculate inverse of |r|^3 real r3i = Constants::G * pow(r2, -1.5); // da = r / |r|^3 // dj = (v / |r|^3 - 3 * (r . v) * r / |r|^5 Vector da = r * r3i; Vector dj = (v - r * (3 * dot(r, v) / r2)) * r3i; // Calculate new acceleration and jerk p[i].acc += da * p[j].mass; p[i].jerk += dj * p[j].mass; p[j].acc -= da * p[i].mass; p[j].jerk -= dj * p[i].mass; // Collision estimation // Metric 1) tau = |r|^2 / |a(j) - a(i)| // Metric 2) tau = |r|^4 / |v|^4 real mij = p[i].mass + p[j].mass; real tau_est_q1 = r2 / (lengthsq(da) * mij * mij); real tau_est_q2 = (r2*r2) / (v2*v2); if (tau_est_q1 < tau_q) tau_q = tau_est_q1; if (tau_est_q2 < tau_q) tau_q = tau_est_q2; } } return sqrt(sqrt(tau_q)); }

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  • Class hierarchy problem (with generic's variance!)

    - by devoured elysium
    The problem: class StatesChain : IState, IHasStateList { private TasksChain tasks = new TasksChain(); ... public IList<IState> States { get { return _taskChain.Tasks; } } IList<ITask> IHasTasksCollection.Tasks { get { return _taskChain.Tasks; } <-- ERROR! You can't do this in C#! I want to return an IList<ITask> from an IList<IStates>. } } Assuming the IList returned will be read-only, I know that what I'm trying to achieve is safe (or is it not?). Is there any way I can accomplish what I'm trying? I wouldn't want to try to implement myself the TasksChain algorithm (again!), as it would be error prone and would lead to code duplication. Maybe I could just define an abstract Chain and then implement both TasksChain and StatesChain from there? Or maybe implementing a Chain<T> class? How would you approach this situation? The Details: I have defined an ITask interface: public interface ITask { bool Run(); ITask FailureTask { get; } } and a IState interface that inherits from ITask: public interface IState : ITask { IState FailureState { get; } } I have also defined an IHasTasksList interface: interface IHasTasksList { List<Tasks> Tasks { get; } } and an IHasStatesList: interface IHasTasksList { List<Tasks> States { get; } } Now, I have defined a TasksChain, that is a class that has some code logic that will manipulate a chain of tasks (beware that TasksChain is itself a kind of ITask!): class TasksChain : ITask, IHasTasksList { IList<ITask> tasks = new List<ITask>(); ... public List<ITask> Tasks { get { return _tasks; } } ... } I am implementing a State the following way: public class State : IState { private readonly TaskChain _taskChain = new TaskChain(); public State(Precondition precondition, Execution execution) { _taskChain.Tasks.Add(precondition); _taskChain.Tasks.Add(execution); } public bool Run() { return _taskChain.Run(); } public IState FailureState { get { return (IState)_taskChain.Tasks[0].FailureTask; } } ITask ITask.FailureTask { get { return FailureState; } } } which, as you can see, makes use of explicit interface implementations to "hide" FailureTask and instead show FailureState property. The problem comes from the fact that I also want to define a StatesChain, that inherits both from IState and IHasStateList (and that also imples ITask and IHasTaskList, implemented as explicit interfaces) and I want it to also hide IHasTaskList's Tasks and only show IHasStateList's States. (What is contained in "The problem" section should really be after this, but I thought puting it first would be way more reader friendly). (pff..long text) Thanks!

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  • Default encoding type for wsHttp binding

    - by user102533
    My understanding was that the default encoding for wsHttp binding is text. However, when I use Fiddler to see the SOAP message, a part of it looks like this: <s:Envelope xmlns:s="http://www.w3.org/2003/05/soap-envelope" xmlns:a="http://www.w3.org/2005/08/addressing" xmlns:u="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd"><s:Header><a:Action s:mustUnderstand="1" u:Id="_2">http://tempuri.org/Services/MyContract/GetDataResponse</a:Action><a:RelatesTo u:Id="_3">urn:uuid:503c5525-f585-4ecd-ac09-24db78526952</a:RelatesTo><o:Security s:mustUnderstand="1" xmlns:o="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd"><u:Timestamp u:Id="uuid-8935f789-fbb7-4c69-9f67-7708373088c5-22"><u:Created>2010-03-08T19:15:50.852Z</u:Created><u:Expires>2010-03-08T19:20:50.852Z</u:Expires></u:Timestamp><c:DerivedKeyToken u:Id="uuid-8935f789-fbb7-4c69-9f67-7708373088c5-18" xmlns:c="http://schemas.xmlsoap.org/ws/2005/02/sc"><o:SecurityTokenReference><o:Reference URI="urn:uuid:b2cbfe07-8093-4f44-8a06-f8b062291643" ValueType="http://schemas.xmlsoap.org/ws/2005/02/sc/sct"/></o:SecurityTokenReference><c:Offset>0</c:Offset><c:Length>24</c:Length><c:Nonce>afOoDygRG7BW+q8+makVIA==</c:Nonce></c:DerivedKeyToken><c:DerivedKeyToken u:Id="uuid-8935f789-fbb7-4c69-9f67-7708373088c5-19" xmlns:c="http://schemas.xmlsoap.org/ws/2005/02/sc"><o:SecurityTokenReference><o:Reference URI="urn:uuid:b2cbfe07-8093-4f44-8a06-f8b062291643" ValueType="http://schemas.xmlsoap.org/ws/2005/02/sc/sct"/></o:SecurityTokenReference><c:Nonce>l4rFsdYKLJTK4tgUWrSBRw==</c:Nonce></c:DerivedKeyToken><e:ReferenceList xmlns:e="http://www.w3.org/2001/04/xmlenc#"><e:DataReference URI="#_1"/><e:DataReference URI="#_4"/></e:ReferenceList><e:EncryptedData Id="_4" Type="http://www.w3.org/2001/04/xmlenc#Element" xmlns:e="http://www.w3.org/2001/04/xmlenc#"><e:EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#aes256-cbc"/><KeyInfo xmlns="http://www.w3.org/2000/09/xmldsig#"><o:SecurityTokenReference><o:Reference ValueType="http://schemas.xmlsoap.org/ws/2005/02/sc/dk" URI="#uuid-8935f789-fbb7-4c69-9f67-7708373088c5-19"/></o:SecurityTokenReference></KeyInfo><e:CipherData><e:CipherValue>dW8B7wGV9tYaxM5ADzY6UuEgB5TFzdy4BZjOtF0NEbHyNevCIAVHMoyA69U4oUjQHMJD5nHS0N4tnJqfJkYellKlpFZcwqruJ1J/TFx9uwLFFAwZ+dSfkDqgKu/1MFzVSY8eyeYKmbPbVEYOHr0lhw3+7wn5NQr3yxvCjlucTAdklIhD72YnVlSVapOW3zgysGt5hStyj+bmIz5hLGyyv6If4HzWjUiru8V3iMM/ss1I+i9sJOD013kr4zaaA937CN9+/aZ2wbDXnYj31UX49uE/vvt9Tl+c4SiydbiX7tp1eNSTx9Ms5O64gb3aUmHEAYOJ19XCrr756ssFZtaE7QOAoPQkFbx9zXy0mb9j1YoPQNG+JAcrN0yoRN1klhccmY+csfYXdq7YBB/KS+u2WnUjQ7SlNFy5qIPxuy5y0Jyedr2diPKLi0gUi+cK49BLQtG/XEShtxFaeMy7zZTrQADxww7kEkhvtmAlmyRbz3oGc+ This doesn't look like text encoding to me (Shouldn't text encoding send data in readable form)? What am I missing? Also, how do I setup binary encoding for wsHttp binding?

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  • Problem on a Floyd-Warshall implementation using c++

    - by Henrique
    I've got a assignment for my college, already implemented Dijkstra and Bellman-Ford sucessfully, but i'm on trouble on this one. Everything looks fine, but it's not giving me the correct answer. Here's the code: void FloydWarshall() { //Also assume that n is the number of vertices and edgeCost(i,i) = 0 int path[500][500]; /* A 2-dimensional matrix. At each step in the algorithm, path[i][j] is the shortest path from i to j using intermediate vertices (1..k-1). Each path[i][j] is initialized to edgeCost(i,j) or infinity if there is no edge between i and j. */ for(int i = 0 ; i <= nvertices ; i++) for(int j = 0 ; j <= nvertices ; j++) path[i][j] = INFINITY; for(int j = 0 ; j < narestas ; j++) //narestas = number of edges { path[arestas[j]->v1][arestas[j]->v2] = arestas[j]->peso; //peso = weight of the edge (aresta = edge) path[arestas[j]->v2][arestas[j]->v1] = arestas[j]->peso; } for(int i = 0 ; i <= nvertices ; i++) //path(i, i) = 0 path[i][i] = 0; //test print, it's working fine //printf("\n\n\nResultado FloydWarshall:\n"); //for(int i = 1 ; i <= nvertices ; i++) // printf("distancia ao vertice %d: %d\n", i, path[1][i]); //heres the problem, it messes up, and even a edge who costs 4, and the minimum is 4, it prints 2. //for k = 1 to n for(int k = 1 ; k <= nvertices ; k++) //for i = 1 to n for(int i = 1 ; i <= nvertices ; i++) //for j := 1 to n for(int j = 1 ; j <= nvertices ; j++) if(path[i][j] > path[i][k] + path[k][j]) path[i][j] = path[i][k] + path[k][j]; printf("\n\n\nResultado FloydWarshall:\n"); for(int i = 1 ; i <= nvertices ; i++) printf("distancia ao vertice %d: %d\n", i, path[1][i]); } im using this graph example i've made: 6 7 1 2 4 1 5 1 2 3 1 2 5 2 5 6 3 6 4 6 3 4 2 means we have 6 vertices (1 to 6), and 7 edges (1,2) with weight 4... etc.. If anyone need more info, i'm up to giving it, just tired of looking at this code and not finding an error.

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  • RNDC fails: permission denied

    - by pawz
    Named works great. It creates a pid in /var/run/named/named.pid as expected. It is listening on port 953 as shown by the log: Apr 20 14:42:38 guchuko named[9115]: command channel listening on 127.0.0.1#953 But whenever I try to run "rndc reload" I get: rndc: 'reload' failed: permission denied What file is it being denied permission to ? It doesn't log anything so I don't know why it's not working. I've compiled bind 9.4-ESV-R1 from source and I've patched it with the mysql mod. my named.conf: options { directory "/var/bind"; forwarders { 203.82.213.101; 203.188.144.1; }; listen-on-v6 { none; }; listen-on { 127.0.0.1; 192.168.0.6; }; pid-file "/var/run/named/named.pid"; }; logging { channel simple_log { file "/var/log/named.log" versions 3 size 5m; severity debug 5; print-time yes; print-severity yes; print-category yes; }; category default { simple_log; }; }; zone "." IN { type hint; file "named.ca"; }; zone "localhost" IN { type master; file "pri/localhost.zone"; allow-update { none; }; notify no; }; include "/etc/rndc.key" my rndc.conf options { default-server 127.0.0.1; default-key "rndc-key"; }; server 127.0.0.1 { key "rndc-key"; }; include "/etc/rndc.key"; my rndc.key: key "rndc-key" { algorithm hmac-md5; secret "XFc8C+yCLK0mIheTSBj41g=="; };

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  • Sending HTML email from PHP

    - by KevinM
    I am trying to send a simple HTML e-mail from PHP. The code below simply results in a blank e-mail in GMail. It also has an empty attachment called 'noname', which is not at all what I want; though that might just be a symptom of it not working. The code I am using is: <?php //define the receiver of the email $to = '[email protected]'; //define the subject of the email $subject = 'Test HTML email'; //create a boundary string. It must be unique //so we use the MD5 algorithm to generate a random hash $random_hash = md5(date('r', time())); //define the headers we want passed. Note that they are separated with \r\n $headers = "From: [email protected]\r\nReply-To: [email protected]"; //add boundary string and mime type specification $headers .= "\r\nContent-Type: multipart/alternative; boundary=\"PHP-alt-".$random_hash."\""; //define the body of the message. ob_start(); //Turn on output buffering ?> --PHP-alt-<?php echo $random_hash; ?> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Hello World!!! This is simple text email message. --PHP-alt-<?php echo $random_hash; ?> MIME-Version: 1.0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: 7bit <h2>Hello World!</h2> <p>This is something with <b>HTML</b>formatting.</p> --PHP-alt-<?php echo $random_hash; ?>-- <? //copy current buffer contents into $message variable and delete current output buffer $message = ob_get_clean(); //send the email $mail_sent = @mail( $to, $subject, $message, $headers ); //if the message is sent successfully print "Mail sent". Otherwise print "Mail failed" echo $mail_sent ? "Mail sent" : "Mail failed";

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  • SQLAlchemy unsupported type error - and table design issues?

    - by Az
    Hi there, back again with some more SQLAlchemy shenanigans. Let me step through this. My table is now set up as so: engine = create_engine('sqlite:///:memory:', echo=False) metadata = MetaData() students_table = Table('studs', metadata, Column('sid', Integer, primary_key=True), Column('name', String), Column('preferences', Integer), Column('allocated_rank', Integer), Column('allocated_project', Integer) ) metadata.create_all(engine) mapper(Student, students_table) Fairly simple, and for the most part I've been enjoying the ability to query almost any bit of information I want provided I avoid the error cases below. The class it is mapped from is: class Student(object): def __init__(self, sid, name): self.sid = sid self.name = name self.preferences = collections.defaultdict(set) self.allocated_project = None self.allocated_rank = 0 def __repr__(self): return str(self) def __str__(self): return "%s %s" %(self.sid, self.name) Explanation: preferences is basically a set of all the projects the student would prefer to be assigned. When the allocation algorithm kicks in, a student's allocated_project emerges from this preference set. Now if I try to do this: for student in students.itervalues(): session.add(student) session.commit() It throws two errors, one for the allocated_project column (seen below) and a similar error for the preferences column: sqlalchemy.exc.InterfaceError: (InterfaceError) Error binding parameter 4 - probably unsupported type. u'INSERT INTO studs (sid, name, allocated_rank, allocated_project) VALUES (?, ?, ?, ?, ?, ?, ?)' [1101, 'Muffett,M.', 1, 888 Human-spider relationships (Supervisor id: 123)] If I go back into my code I find that, when I'm copying the preferences from the given text files, it actually refers to the Project class which is mapped to a dictionary, using the unique project id's (pid) as keys. Thus, as I iterate through each student via their rank and to the preferences set, it adds not a project id, but the reference to the project id from the projects dictionary. students[sid].preferences[int(rank)].add(projects[int(pid)]) Now this is very useful to me since I can find out all I want to about a student's preferred projects without having to run another check to pull up information about the project id. The form you see in the error has the object print information passed as: return "%s %s (Supervisor id: %s)" %(self.proj_id, self.proj_name, self.proj_sup) My questions are: I'm trying to store an object in a database field aren't I? Would the correct way then, be copying the project information (project id, name, etc) into its own table, referenced by the unique project id? That way I can just have the project id field for one of the student tables just be an integer id and when I need more information, just join the tables? So and so forth for other tables? If the above makes sense, then how does one maintain the relationship with a column of information in one table which is a key index on another table? Does this boil down into a database design problem? Are there any other elegant ways of accomplishing this? Apologies if this is a very long-winded question. It's rather crucial for me to solve this, so I've tried to explain as much as I can, whilst attempting to show that I'm trying (key word here sadly) to understand what could be going wrong.

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