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• c# webbrowser | pushed realtime quotes

  - by Eric

  Hi, I am programmer and share trader. Before I have written a day trading application. Until last week it was possible to fetch realtime quotes from http://aktien.boerse.de/aktien_startseite.php?view=2&order=name%20asc&liste=prime&page=0 . Every time the site was surfed the quotes had changed. The HTML contents could then be decoded with regular expressions (regex). Problem They have stopped this service by today. Now the quotes are not realtime when surfing on the page. The only way to get stock quotes now is to use pushed quotes "Push starten"-Button. However I do not know how to basically fetch them in C#. When I create a webbrowser element the only way which I know to get the push quotes out of it is to give the webbrowser element the focus send key ctrl+A and ctrl+C and insert the data some where for decoding. This is not desired since the control is moved away from the user and in case some other control is clicked during the process this may result in unexpected behaviour. Question So is there a proper way to decode push stock quotes in C#? Thanks a lot in advance, --eric

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• Why is graphviz drawing two arrows, and using a weird order?

  - by dmd

  Why is graphviz drawing two arrows from uncap_spike to peel, and why is it drawing peel to the right of hang? I want uncap_spike - peel - hang - spike, in that order, with one edge between each. digraph hangers { compound=true fontname="Gill Sans" node [fontname="Gill Sans" shape=box fillcolor=white style="rounded, filled"] edge [fontname="Gill Sans"] subgraph cluster_prep { style="filled" label=Prep gather [shape=Mrecord label="{gather | EtOH swab\nvented tubing}"] uncap_bottle [label="uncap bottle"] uncap_spike [label="uncap spike"] swab [shape=Mrecord label="{swab EtOH | wait 30 seconds for sterility}"] gather -> uncap_bottle -> swab -> uncap_spike {rank=same gather uncap_bottle swab uncap_spike} } subgraph cluster_hang { style=filled label=Hang {rank=same peel hang} } {rank=same uncap_spike -> peel -> hang -> spike -> prime} hang -> rip [color=firebrick] rip [label="eyelet\nripped" style="filled" shape=octagon regular fontcolor=white fontsize=10 width=.5 fixedsize color=firebrick fillcolor=firebrick ] swab -> not_sterile [color=firebrick] not_sterile [label="not\nsterile" style="filled" shape=octagon regular fontcolor=white fontsize=10 width=.5 fixedsize color=firebrick fillcolor=firebrick ] }

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• Does isEmpty method in Stream evaluate the whole Stream?

  - by abhin4v

  In Scala, does calling isEmtpy method on an instance of Stream class cause the stream to be evaluated completely? My code is like this: import Stream.cons private val odds: Stream[Int] = cons(3, odds.map(_ + 2)) private val primes: Stream[Int] = cons(2, odds filter isPrime) private def isPrime(n: Int): Boolean = n match { case 1 => false case 2 => true case 3 => true case 5 => true case 7 => true case x if n % 3 == 0 => false case x if n % 5 == 0 => false case x if n % 7 == 0 => false case x if (x + 1) % 6 == 0 || (x - 1) % 6 == 0 => true case x => primeDivisors(x) isEmpty } import Math.{sqrt, ceil} private def primeDivisors(n: Int) = primes takeWhile { _ <= ceil(sqrt(n))} filter {n % _ == 0 } So, does the call to isEmpty on the line case x => primeDivisors(x) isEmpty cause all the prime divisors to be evaluated or only the first one?

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• performance of large number calculations in python (python 2.7.3 and .net 4.0)

  - by g36

  There is a lot of general questions about python performance in comparison to other languages. I've got more specific example: There are two simple functions wrote in python an c#, both checking if int number is prime. python: import time def is_prime(n): num =n/2 while num >1: if n % num ==0: return 0 num-=1 return 1 start = time.clock() probably_prime = is_prime(2147483629) elapsed = (time.clock() - start) print 'time : '+str(elapsed) and C#: using System.Diagnostics; public static bool IsPrime(int n) { int num = n/2; while(num >1) { if(n%num ==0) { return false; } num-=1; } return true; } Stopwatch sw = new Stopwatch(); sw.Start(); bool result = Functions.IsPrime(2147483629); sw.Stop(); Console.WriteLine("time: {0}", sw.Elapsed); And times ( which are surprise for me as a begginer in python:)): Python: 121s; c#: 6s Could You explain where does this big diffrence come from ?

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• Refresh a Div that has a Google ad inside it

  - by Abs

  Hello all, I have a div that holds a google ad. My website is mostly AJAX and there is no need for a browser refresh. That means my ads will not refresh either, which isnt ideal, a user staring at one ad all day. So I wanted a way to refresh a particular div on a page. I found many solutions but they didnt work. For example, using JQuery's html function: $("#ads").html("google ad script here"); This managed to refresh the whole page no idea how. I can also make an AJAX request to a HTML page that contains the google ad but I am guessing it will have the same effect as the above attempt. I do not want to use iFrames. Is there any other option open to me? My pea brain can not think of anymore. :) Thanks you for any help. EDIT: It is allowed since I will be initiating the refresh only when a user clicks a link. A prime example is Yahoo Mail - their new AJAX mailbox uses this same method, when a user clicks a link then a new ad is shown.

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• How To Generate Parameter Set for the Diffie-Hellman Key Agreement Algorithm in Android

  - by sebby_zml

  Hello everyone, I am working on mobile/server security related project. I am now stuck in generating a Diffie-Hellman key agreement part. It works fine in server side program but it is not working in mobile side. Thus, I assume that it is not compactible with Android. I used the following class to get the parameters. It returns a comma-separated string of 3 values. The first number is the prime modulus P. The second number is the base generator G. The third number is bit size of the random exponent L. My question is is there anything wrong with the code or it is not compactible for android?What kind of changes should I do? Your suggestion and guidance would be very much help for me. Thanks a lot in advance. public static String genDhParams() { try { // Create the parameter generator for a 1024-bit DH key pair AlgorithmParameterGenerator paramGen = AlgorithmParameterGenerator.getInstance("DH"); paramGen.init(1024); // Generate the parameters AlgorithmParameters params = paramGen.generateParameters(); DHParameterSpec dhSpec = (DHParameterSpec)params.getParameterSpec(DHParameterSpec.class); // Return the three values in a string return ""+dhSpec.getP()+","+dhSpec.getG()+","+dhSpec.getL(); } catch (NoSuchAlgorithmException e) { } catch (InvalidParameterSpecException e) { } return null; } Regards, Sebby

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• What is the best anti-crack scheme for your trial or subscription software?

  - by gmatt

  Writing code takes time and effort and just like any other human being we need to live by making an income (save for the few that are actually self sustainable.) Here are 3 general schemes to make a living: Independent developers can offer a trial then purchase scheme. An alternative is an open source base application with pay extensions. A last (probably least popular with customers) scheme is to enforce some kind of subscription. Then the price of the software pales in comparison to the long term subscription fees. So, my question would be a hypothetical one. Suppose that you invest thousands of hours into developing an application. Now suppose you can choose any one of the three options to make a living off this application--or any other option you want--and suppose you have a very real fear of loosing 80% of your revenue to a cracked version if one can be made. To be clear this application does not require the internet to perform all its useful functions, that is, your application is a prime candidate to be a cracked release on some website. Which option would you feel most comfortable with defending yourself against this possible situation and briefly describe why this option would be the best.

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• "Priming" a whole database in MSSQL for first-hit speed

  - by David Spillett

  For a particular apps I have a set of queries that I run each time the database has been restarted for any reason (server reboot usually). These "prime" SQL Server's page cache with the common core working set of the data so that the app is not unusually slow the first time a user logs in afterwards. One instance of the app is running on an over-specced arrangement where the SQL box has more RAM than the size of the database (4Gb in the machine, the DB is under 1.5Gb currently and unlikely to grow too much relative to that in the near future). Is there a neat/easy way of telling SQL Server to go away and load everything into RAM? It could be done the hard way by having a script scan sysobjects & sysindexes and running SELECT * FROM <table> WITH(INDEX(<index_name>)) ORDER BY <index_fields> for every key and index found, which should cause every used page to be read at least once and so be in RAM, but is there a cleaner or more efficient way? All planned instances where the database server is stopped are out-of-normal-working-hours (all the users are at most one timezone away and unlike me none of them work at silly hours) so such a process (until complete) slowing down users more than the working set not being primed at all would is not an issue.

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• Project Euler problem 214, How can i make it more efficient?

  - by Once

  I am becoming more and more addicted to the Project Euler problems. However since one week I am stuck with the #214. Here is a short version of the problem: PHI() is Euler's totient function, i.e. for any given integer n, PHI(n)=numbers of k<=n for which gcd(k,n)=1. We can iterate PHI() to create a chain. For example starting from 18: PHI(18)=6 = PHI(6)=2 = PHI(2)=1. So starting from 18 we get a chain of length 4 (18,6,2,1) The problem is to calculate the sum of all primes less than 40e6 which generate a chain of length 25. I built a function that calculates the chain length of any number and I tested it for small values: it works well and fast. sum of all primes<=20 which generate a chain of length 4: 12 sum of all primes<=1000 which generate a chain of length 10: 39383 Unfortunately my algorithm doesn't scale well. When I apply it to the problem, it takes several hours to calculate... so I stop it because the Project Euler problems must be solved in less than one minute. I thought that my prime detection function might be slow so I fed the program with a list of primes <40e6 to avoid the primality test... The code runs now a little bit faster, but there is still no way to get a solution in less than a few hours (and I don't want this). So is there any "magic trick" that I am missing here ? I really don't understand how to be more efficient on this one... I am not asking for the solution, because fighting with optimization is all the fun of Project Euler. However, any small hint that could put me on the right track would be welcome. Thanks !

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• How to "reduce" a hash?

  - by Julien Lebosquain

  Suppose I have any "long" hash, like a 16 bytes MD5 or a 20 bytes SHA1. I want to reduce this hash to fit on 4 bytes, for GetHashCode() purposes. First, I'm perfectly aware that I'll get more collisions. That's totally fine in my case, but I'd still prefer to get the less possible collisions. There are several solutions to my problem: I could take the 4 first bytes of the hash. I could take the 4 last bytes of the hash. I could take 4 random bytes of the hash. I could generate a hash of the hash, involving classic prime numbers multiplications. Are there other solutons I didn't think about? And more importantly, what method will give me the most unique hash code? I'm currently supposing they're almost equivalent. Microsoft choose that the public key token of an assembly is the last 8 bytes of the SHA1 hash of its public key, so I'll probably go for this solution but I'd like to know why.

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• Project Euler, Problem 10 java solution not working

  - by Dennis S

  Hi, I'm trying to find the sum of the prime numbers < 2'000'000. This is my solution in java but I can't seem get the correct answer. Please give some input on what could be wrong and general advice on the code is appreciated. Printing 'sum' gives: 1308111344, which is incorrect. /* The sum of the primes below 10 is 2 + 3 + 5 + 7 = 17. Find the sum of all the primes below two million. */ class Helper{ public void run(){ Integer sum = 0; for(int i = 2; i < 2000000; i++){ if(isPrime(i)) sum += i; } System.out.println(sum); } private boolean isPrime(int nr){ if(nr == 2) return true; else if(nr == 1) return false; if(nr % 2 == 0) return false; for(int i = 3; i < Math.sqrt(nr); i += 2){ if(nr % i == 0) return false; } return true; } } class Problem{ public static void main(String[] args){ Helper p = new Helper(); p.run(); } }

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• Javascript CS-PRNG - 64-bit random

  - by Jack

  Hi, I need to generate a cryptographically secure 64-bit unsigned random integer in Javascript. The first problem is that Javascript only allows 64-bit signed integers, so 9223372036854775808 is the biggest supported integer without going into floating point use I think? To fix this I can use a big number library, no problem. My Method: var randNum = SHA256( randBigInt(128, 0) ) % 2^64; Where SHA256() is a secure hash function and randBigInt() is defined below as a non-crypto PRNG, im giving it a 128bit seed so brute force shouldn't be a problem. randBigInt(n,s) //return an n-bit random BigInt (n>=1). If s=1, then the most significant of those n bits is set to 1. Is this a secure method to generate a cryptographically secure 64-bit random int? And importantly does taking the 2^64 mod guarantee 100% I have a 64-bit number? An abstract example, say this number is prime (it isn't i know), I will use it in the Galois Field [2^p], where p must be 64bits so that every possible 1-63bit number is a field element. In this query, my random int must be larger than any 63-bit number. And Im not sure im correct in taking the 2^64 mod of a 256bit hash output. Thanks (hope that makes sense)

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• Why isn't my submit button centered?

  - by William

  For some reason my submit button isn't centered. http://prime.programming-designs.com/test_forum/viewboard.php?board=0 #submitbutton{ margin: auto; border: 1px solid #DBFEF8; background-color: #DBFEF8; color: #000000; margin-top: 5px; width: 100px; height: 20px; } here's the html. <form method=post action=add_thread.php?board=<?php echo''.$board.''; ?>> <div id="formdiv"> <div class="fieldtext1">Name</div> <div class="fieldtext1">Trip</div> <input type="text" name=name size=25 /> <input type="text" name=trip size=25 /> <div class="fieldtext2">Comment</div> <textarea name=post rows="4" cols="70"></textarea> <div class="fieldtext2">Fortune</div> <input type="checkbox" name="fortune" value="fortune" /> </div> <input type=submit value="Submit" id="submitbutton"> </form>

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• Problem with Boost::Asio for C++

  - by Martin Lauridsen

  Hi there, For my bachelors thesis, I am implementing a distributed version of an algorithm for factoring large integers (finding the prime factorisation). This has applications in e.g. security of the RSA cryptosystem. My vision is, that clients (linux or windows) will download an application and compute some numbers (these are independant, thus suited for parallelization). The numbers (not found very often), will be sent to a master server, to collect these numbers. Once enough numbers have been collected by the master server, it will do the rest of the computation, which cannot be easily parallelized. Anyhow, to the technicalities. I was thinking to use Boost::Asio to do a socket client/server implementation, for the clients communication with the master server. Since I want to compile for both linux and windows, I thought windows would be as good a place to start as any. So I downloaded the Boost library and compiled it, as it said on the Boost Getting Started page: bootstrap .\bjam It all compiled just fine. Then I try to compile one of the tutorial examples, client.cpp, from Asio, found (here.. edit: cant post link because of restrictions). I am using the Visual C++ compiler from Microsoft Visual Studio 2008, like this: cl /EHsc /I D:\Downloads\boost_1_42_0 client.cpp But I get this error: /out:client.exe client.obj LINK : fatal error LNK1104: cannot open file 'libboost_system-vc90-mt-s-1_42.lib' Anyone have any idea what could be wrong, or how I could move forward? I have been trying pretty much all week, to get a simple client/server socket program for c++ working, but with no luck. Serious frustration kicking in. Thank you in advance.

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• SVG rotation animation having problems on chrome for jelly bean, is there a workaround?

  - by Metalskin

  I've got a strange problem with chrome on jellybean running svg animations triggered from javascript. This JSFiddle example works fine on chrome and firefox on linux, but when I run it on android with chrome I get the final step of the animation painted at the beginning of the animation. I've tried this on both an Nexus 7 and Transformer Prime, they both have the problem. I've tested using firefox on the android devices and the problem doesn't exist. So I'm presuming that it's a defect with chrome. However I've seen other animations using svg that do not have this problem in chrome on jellybean. Is anyone aware of a way to get around this problem, or is there something that I'm doing in my animation/js that is a possible cause of the problem? I've now created a bug report at code.google.com, however I still need a workaround, if anyone can help me (or in case I'm doing something stupid). I've now discovered that this is reproducible on chrome for linux (and I suspect windows). If you click on the button to start the animation before the previous animation has completed then the problem occurs. In this case the hand is drawn at the end of the 45 degree sweep before it starts the sweep. I now suspect that I should be calling something to stop the animation before I change the animation. Anyway, hopefully someone can resolve this problem.

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• List of Big-O for PHP functions?

  - by Kendall Hopkins

  After using PHP for a while now, I've noticed that not all PHP built in functions as fast as expected. Consider the below two possible implementations of a function that finds if a number is prime using a cached array of primes. //very slow for large $prime_array $prime_array = array( 2, 3, 5, 7, 11, 13, .... 104729, ... ); $result_array = array(); foreach( $array_of_number => $number ) { $result_array[$number] = in_array( $number, $large_prime_array ); } //still decent performance for large $prime_array $prime_array => array( 2 => NULL, 3 => NULL, 5 => NULL, 7 => NULL, 11 => NULL, 13 => NULL, .... 104729 => NULL, ... ); foreach( $array_of_number => $number ) { $result_array[$number] = array_key_exists( $number, $large_prime_array ); } This is because in_array is implemented with a linear search O(n) which will linearly slow down as $prime_array grows. Where the array_key_exists function is implemented with a hash lookup O(1) which will not slow down unless the hash table gets extremely populated (in which case it's only O(logn)). So far I've had to discover the big-O's via trial and error, and occasionally looking at the source code. Now for the question... I was wondering if there was a list of the theoretical (or practical) big O times for all* the PHP built in functions. *or at least the interesting ones For example find it very hard to predict what the big O of functions listed because the possible implementation depends on unknown core data structures of PHP: array_merge, array_merge_recursive, array_reverse, array_intersect, array_combine, str_replace (with array inputs), etc.

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• Questions about the Backpropogation Algorithm

  - by Colemangrill

  I have a few questions concerning backpropogation. I'm trying to learn the fundamentals behind neural network theory and wanted to start small, building a simple XOR classifier. I've read a lot of articles and skimmed multiple textbooks - but I can't seem to teach this thing the pattern for XOR. Firstly, I am unclear about the learning model for backpropogation. Here is some pseudo-code to represent how I am trying to train the network. [Lets assume my network is setup properly (ie: multiple inputs connect to a hidden layer connect to an output layer and all wired up properly)]. SET guess = getNetworkOutput() // Note this is using a sigmoid activation function. SET error = desiredOutput - guess SET delta = learningConstant * error * sigmoidDerivative(guess) For Each Node in inputNodes For Each Weight in inputNodes[n] inputNodes[n].weight[j] += delta; // At this point, I am assuming the first layer has been trained. // Then I recurse a similar function over the hidden layer and output layer. // The prime difference being that it further divi's up the adjustment delta. I realize this is probably not enough to go off of, and I will gladly expound on any part of my implementation. Using the above algorithm, my neural network does get trained, kind of. But not properly. The output is always XOR 1 1 [smallest number] XOR 0 0 [largest number] XOR 1 0 [medium number] XOR 0 1 [medium number] I can never train the [1,1] [0,0] to be the same value. If you have any suggestions, additional resources, articles, blogs, etc for me to look at I am very interested in learning more about this topic. Thank you for your assistance, I appreciate it greatly!

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• Project Euler, Problem 10 java solution now working

  - by Dennis S

  Hi, I'm trying to find the sum of the prime numbers < 2'000'000. This is my solution in java but I can't seem get the correct answer. Please give some input on what could be wrong and general advice on the code is appreciated. Printing 'sum' gives: 1308111344, which is incorrect. /* The sum of the primes below 10 is 2 + 3 + 5 + 7 = 17. Find the sum of all the primes below two million. */ class Helper{ public void run(){ Integer sum = 0; for(int i = 2; i < 2000000; i++){ if(isPrime(i)) sum += i; } System.out.println(sum); } private boolean isPrime(int nr){ if(nr == 2) return true; else if(nr == 1) return false; if(nr % 2 == 0) return false; for(int i = 3; i < Math.sqrt(nr); i += 2){ if(nr % i == 0) return false; } return true; } } class Problem{ public static void main(String[] args){ Helper p = new Helper(); p.run(); } }

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• Int - number too large. How to get program to fail?

  - by Dave

  Hi Problem: How do you get a program to fail if a number goes beyond the bounds of its type? This code below gives the wrong answer for sum of primes under 2 million as I'd used an int instead of a long. [TestMethod] public void CalculateTheSumOfPrimesBelow2million() { int result = PrimeTester.calculateTheSumOfPrimesBelow(2000000); // 2million Assert.AreEqual(1, result); // 1,179,908,154 .. this was what I got with an int... // correct answer was 142,913,828,922 with a long } public static class PrimeTester { public static int calculateTheSumOfPrimesBelow(int maxPrimeBelow) { // we know 2 is a prime number int sumOfPrimes = 2; int currentNumberBeingTested = 3; while (currentNumberBeingTested < maxPrimeBelow) { double squareRootOfNumberBeingTested = (double)Math.Sqrt(currentNumberBeingTested); bool isPrime = true; for (int i = 2; i <= squareRootOfNumberBeingTested; i++) { if (currentNumberBeingTested % i == 0) { isPrime = false; break; } } if (isPrime) sumOfPrimes += currentNumberBeingTested; currentNumberBeingTested += 2; // as we don't want to test even numbers } return sumOfPrimes; } }

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• Why is my php script freezing?

  - by William

  What is causing my php code to freeze? I know it's cause of the while loop, but I have $max_threads--; at the end so it shouldn't do that. <html> <head> <?php $db = mysql_connect("host","name","pass") or die("Can't connect to host"); mysql_select_db("dbname",$db) or die("Can't connect to DB"); $sql_result = mysql_query("SELECT MAX(Thread) FROM test_posts", $db); $rs = mysql_fetch_row($sql_result); $max_threads = $rs[0]; $board = $_GET['board']; ?> </head> <body> <?php While($max_threads >= 0) { $sql_result = mysql_query("SELECT MIN(ID) FROM test_posts WHERE Thread=".$max_threads."", $db); $rs = mysql_fetch_row($sql_result); $sql_result = mysql_query("SELECT post FROM test_posts WHERE ID=".$rs[0]."", $db); $post = mysql_fetch_row($sql_result); $sql_result = mysql_query("SELECT name FROM test_posts WHERE ID=".$rs[0]."", $db); $name = mysql_fetch_row($sql_result); $sql_result = mysql_query("SELECT trip FROM test_posts WHERE ID=".$rs[0]."", $db); $trip = mysql_fetch_row($sql_result); if(!empty($post)) echo'<div class="postbox"><h4>'.$name[0].'['.$trip[0].']</h4><hr />' . $post[0] . '<br /><hr />[<a href="http://prime.programming-designs.com/test_forum/viewthread.php?thread='.$max_threads.'">Reply</a>]</div>'; $max_threads--; } ?> </body> </html>

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• Strange type-related error

  - by vsb

  I wrote following program: isPrime x = and [x `mod` i /= 0 | i <- [2 .. truncate (sqrt x)]] primes = filter isPrime [1 .. ] it should construct list of prime numbers. But I got this error: [1 of 1] Compiling Main ( 7/main.hs, interpreted ) 7/main.hs:3:16: Ambiguous type variable `a' in the constraints: `Floating a' arising from a use of `isPrime' at 7/main.hs:3:16-22 `RealFrac a' arising from a use of `isPrime' at 7/main.hs:3:16-22 `Integral a' arising from a use of `isPrime' at 7/main.hs:3:16-22 Possible cause: the monomorphism restriction applied to the following: primes :: [a] (bound at 7/main.hs:3:0) Probable fix: give these definition(s) an explicit type signature or use -XNoMonomorphismRestriction Failed, modules loaded: none. If I specify signature for isPrime function explicitly: isPrime :: Integer -> Bool isPrime x = and [x `mod` i /= 0 | i <- [2 .. truncate (sqrt x)]] I can't even compile isPrime function: [1 of 1] Compiling Main ( 7/main.hs, interpreted ) 7/main.hs:2:45: No instance for (RealFrac Integer) arising from a use of `truncate' at 7/main.hs:2:45-61 Possible fix: add an instance declaration for (RealFrac Integer) In the expression: truncate (sqrt x) In the expression: [2 .. truncate (sqrt x)] In a stmt of a list comprehension: i <- [2 .. truncate (sqrt x)] 7/main.hs:2:55: No instance for (Floating Integer) arising from a use of `sqrt' at 7/main.hs:2:55-60 Possible fix: add an instance declaration for (Floating Integer) In the first argument of `truncate', namely `(sqrt x)' In the expression: truncate (sqrt x) In the expression: [2 .. truncate (sqrt x)] Failed, modules loaded: none. Can you help me understand, why am I getting these errors?

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• Interpretation of range(n) and boolean list, one-to-one map, simpler?

  - by HH

  #!/usr/bin/python # # Description: bitwise factorization and then trying to find # an elegant way to print numbers # Source: http://forums.xkcd.com/viewtopic.php?f=11&t=61300#p2195422 # bug with large numbers such as 99, but main point in simplifying it # def primes(n): # all even numbers greater than 2 are not prime. s = [False]*2 + [True]*2 + [False,True]*((n-4)//2) + [False]*(n%2) i = 3; while i*i < n: # get rid of ** and skip even numbers. s[i*i : n : i*2] = [False]*(1+(n-i*i)//(i*2)) i += 2 # skip non-primes while not s[i]: i += 2 return s # TRIAL: can you find a simpler way to print them? # feeling the overuse of assignments but cannot see a way to get it simpler # p = 49 boolPrimes = primes(p) numbs = range(len(boolPrimes)) mydict = dict(zip(numbs, boolPrimes)) print([numb for numb in numbs if mydict[numb]]) Something I am looking for, can you get TRIAL to be of the extreme simplicity below? Any such method? a=[True, False, True] b=[1,2,3] b_a # any such simple way to get it evaluated to [1,3] # above a crude way to do it in TRIAL

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• Which Android hardware devices should I test on? [closed]

  - by Tchami

  Possible Duplicate: What hardware devices do you test your Android apps on? I'm trying to compile a list of Android hardware devices that it would make sense to buy and test against if you want to target an as broad audience as possible, while still not buying every single Android device out there. I know there's a lot of information regarding screen sizes and Android versions available elsewhere, but: when developing for Android it's not terribly useful to know if the screen size of a device is 480x800 or 320x240, unless you feel like doing the math to convert that into Android "units" (i.e. small, normal, large or xlarge screens, and ldpi, mdpi, hdpi or xhdpi densities). Even knowing the dimensions of a device, you cannot be sure of the actual Android units as there's some overlap, see Range of screens supported in the Android documentation Taking into account the distribution of Platform versions and Screen Sizes and Densities, below is my current list based on information from the Wikipedia article on Comparison of Android devices. I'm fairly sure the information in this list is correct, but I'd welcome any suggestions/changes. Phones | Model | Android Version | Screen Size | Density | | HTC Wildfire | 2.1/2.2 | Normal | mdpi | | HTC Tattoo | 1.6 | Normal | mdpi | | HTC Hero | 2.1 | Normal | mdpi | | HTC Legend | 2.1 | Normal | mdpi | | Sony Ericsson Xperia X8 | 1.6/2.1 | Normal | mdpi | | Motorola Droid | 2.0-2.2 | Normal | hdpi | | Samsung Galaxy S II | 2.3 | Normal | hdpi | | Samsung Galaxy Nexus | 4.0 | Normal | xhdpi | | Samsung Galaxy S III | 4.0 | Normal | xhdpi | **Tablets** | Model | Android Version | Screen Size | Density | | Samsung Galaxy Tab 7" | 2.2 | Large | hdpi | | Samsung Galaxy Tab 10" | 3.0 | X-Large | mdpi | | Asus Transformer Prime | 4.0 | X-Large | mdpi | | Motorola Xoom | 3.1/4.0 | X-Large | mdpi | N.B.: I have seen (and read) other posts on SO on this subject, e.g. Which Android devices should I test against? and What hardware devices do you test your Android apps on? but they don't seem very canonical. Maybe this should be marked community wiki?

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• Configuring Windows 2003 As A Router

  - by Sean M

  I am trying to configure a Windows 2003 server to act as a router, so that the two subnetworks that I'm dealing with can communicate with one another without NAT. I am mostly sure that I have configured Windows 2003 incorrectly, and I'm finding it very difficult to drill down through Google results to something helpful. I have a 192.168.1.0/24 network that is my "production" network (in the sense that I'm in trouble if I screw it up) and a 10.0.0.0/8 network that is my test network. The 192.168.1.0 network is ruled by a gateway whose routing table looks like this (my address redacted): The Windows 2003 server, "prime," is multihomed. Its network adapters are at 192.168.1.122, (as seen above), 10.0.0.1, and 10.0.0.2. I added the Routing and Remote Access role to it, and enabled LAN routing. I do not have it using RIP or other routing protocols. Its current routing table is shown below. To me, it looks like all of the right routes are there for traffic to pass between the 192.168.1.0 network and the 10.0.0.0 network. However, traffic does not pass. The 10.0.0.11 and .12 clients cannot be contacted from the 192.168.1.0 network. When I use traceroute to try to get to them, the trace gets to the Windows 2003 server's 192.168.1.122 address, then produces nothing but "* * *" timeouts. When I try to traceroute to 192.168.1.1 from a 10.0.0.0-network client, I get "destination host unreachable." However, I know that the routing is working at least a little, because from the 192.168.1.0 network, I can connect to the Windows server just fine by referring to it as 10.0.0.1. What static routes would allow me to contact 10.0.0.11 and .12 from the 192.168.1.0 network? Is it possible to tell the Windows server "since you are a DHCP/DNS server, you already know routes to get to machines that are getting IP addresses from you, please add those to your routing table" ? Will using RIP or OSPF on the Windows server actually be helpful in this situation?

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• Setting up a home server - what to use? (ZFS vs btrfs, BSD vs Linux, misc other requirements)

  - by monch1962

  I need to get all our home content off individual machines and onto a central server. What I'd like to have is the metaphorical "server under the stairs". Stuff we need: expandable storage. I want to be able to add extra disc as we go along, with minimal maintenance required. Currently we've got about 3Tb of files we need to host, and that's likely to grow by another Tb every 6-12 months based on recent history. I need to be able to add additional disc with minimal pain needs to store all the media (i.e. photos, video, music) we have, and run services to serve the various devices we have in the house to playback (e.g. DAAP so we can play stuff through iTunes, ccxstream so we can play stuff over XBMC). DAAP and ccxstream are needed now, but we also need to support new standards as they emerge (so a closed-box solution isn't going to work) RAID 5, or something broadly equivalent (e.g. RAID-Z) BitTorrent client ssh, NFS, Samba access snapshot capability (as in ZFS), so we can snapshot individual file systems regularly and rollback when my kids delete their school assignments the day before they're due... ability to recover quickly from power outages (it's not unusual for us to have power outages that last longer than our UPS' batteries) FOSS software a modern distributed version control system running on the box, such as Mercurial Stuff I'd like to have on the server, but can live without: PVR capability, so I could record TV to the box Web server. We currently run a small Web server on a very old box, and I'd ideally like to turn the old box off and move the content to the new server just to save some electricity Nagios + mrtg I've been looking at using a EEE Box as the server, primarily because I can get them cheap and they don't consume much power. The choice of OS and file system is more difficult, from what I've found: I've got most experience with various Linux distros, but am happy to use another Unix FreeBSD and OpenSolaris seem to be the best choices for hosting ZFS OpenSolaris' hardware support is nowhere near as good as e.g. Ubuntu btrfs, while looking very good, doesn't seem ready for prime-time yet ZFS doesn't let you (easily?) add new discs to a RAID5 or RAID-Z reading around, it seems that ZFS is a bit short of tools for recovering lost data At the moment, I'm leaning towards running FreeNAS+ZFS, but I'm concerned about the requirement to be able to add new disc on a fairly regular basis to an existing RAID-Z. Can anyone provide some recommendations, or share experiences? Thanks in advance

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