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• Doubts About Core Data NSManagedObject Deep Copy

  - by Jigzat

  Hello everyone, I have a situation where I must copy one NSManagedObject from the main context into an editing context. It sounds unnecessary to most people as I have seen in similar situations described in Stackoverflow but I looks like I need it. In my app there are many views in a tab bar and every view handles different information that is related to the other views. I think I need multiple MOCs since the user may jump from tab to tab and leave unsaved changes in some tab but maybe it saves data in some other tab/view so if that happens the changes in the rest of the views are saved without user consent and in the worst case scenario makes the app crash. For adding new information I got away by using an adding MOC and then merging changes in both MOCs but for editing is not that easy. I saw a similar situation here in Stackoverflow but the app crashes since my data model doesn't seem to use NSMutableSet for the relationships (I don't think I have a many-to-many relationship, just one-to-many) I think it can be modified so I can retrieve the relationships as if they were attributes for (NSString *attr in relationships) { [cloned setValue:[source valueForKey:attr] forKey:attr]; } but I don't know how to merge the changes of the cloned and original objects. I think I could just delete the object from the main context, then merge both contexts and save changes in the main context but I don't know if is the right way to do it. I'm also concerned about database integrity since I'm not sure that the inverse relationships will keep the same reference to the cloned object as if it were the original one. Can some one please enlighten me about this?

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• Append a dynamically changing watermark to a PDF in SharePoint

  - by ccomet

  This is primarily a question of possibilities more than instructions. I'm a programming consultant working on a WSS project site system for my client. We have a document library in which files are uploaded to go through a complex approval process. With multiple stages in this process, we have an extra field which dictates what the current status of the document is. Now, my client has become enamored with the idea of PDF watermarking. He wants the document (which is already a PDF) to be affixed with a watermark corresponding to the current status, such that with each stage of the approval process the watermark will change. One method, the traditional method for PDF watermarking, of accomplishing this is to have one "clean" copy of the document somewhere hidden on the site, and create a new PDF from it that has the watermark at each stage of the approval process. Since the filename will never change, this new PDF can be uploaded continually to a public library, always overwriting the old version and simulating a "dynamically changing watermark". However, in the various stages there will also be people uploading clean copies with corrections and suggestions, nevermind the complex nature of juggling around two libraries and the fact we double the number of files stored. My client and I agree that this is not a practical path to choose. What we would like to do is be able to "modify" the watermark in a PDF, so that we only have to keep one copy of the file. Unfortunately, from what I've seen, in most cases when you make something like a watermark, which in its nature is supposed to be "unmodifyable", you won't be able to edit it later. So, is it possible to have a part of a PDF which cannot be changed by anyone who downloads the file, but can be changed as part of a workflow or other object model process? Thanks in advance!

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• RESTful API design question - how should one allow users to create new resource instances?

  - by Tamás

  I'm working in a research group where we intend to publish implementations of some of the algorithms we develop on the web via a RESTful API. Most of these algorithms work on small to medium size datasets, and in many cases, a user of our services might want to run multiple queries (with different parameters) on the same dataset, so for me it seems reasonable to allow users to upload their datasets in advance and refer to them in their queries later. In this sense, a dataset could be a resource in my API, and an algorithm could be another. My question is: how should I let the users upload their own datasets? I cannot simply let users upload their data to /dataset/dataset_id as letting the users invent their own dataset_ids might result in ID collision and users overwriting each other's datasets by accident. (I believe one of the most frequently used dataset ID would be test). I think an ideal way would be to have a dedicated URL (like /dataset/upload) where users can POST their datasets and the response would contain a unique ID under which the dataset was stored, but I'm not sure that it does not violate the basic principles of REST. What is the preferred way of dealing with such scenarios?

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• How do I get the F1-F12 keys to switch screens in gnu screen in cygwin when connecting via SSH?

  - by Mikey

  I'm connecting to a desktop running cygwin via SSH from the terminal app in Mac OS X. I have already started screen on the cygwin side and can connect to it over the SSH session. Furthermore, I have the following in the .screenrc file: bindkey -k k1 select 1 # F1 = screen 1 bindkey -k k2 select 2 # F2 = screen 2 bindkey -k k3 select 3 # F3 = screen 3 bindkey -k k4 select 4 # F4 = screen 4 bindkey -k k5 select 5 # F5 = screen 5 bindkey -k k6 select 6 # F6 = screen 6 bindkey -k k7 select 7 # F7 = screen 7 bindkey -k k8 select 8 # F8 = screen 8 bindkey -k k9 select 9 # F9 = screen 9 bindkey -k F1 prev # F11 = prev bindkey -k F2 next # F12 = next However, when I start multiple windows in screen and attempt to switch between them via the function keys, all I get is a beep. I have tried various settings for $TERM (e.g. ansi, cygwin, xterm-color, vt100) and they don't really seem to affect anything. I have verified that the terminal app is in fact sending the escape sequence for the function key that I'm expecting and that my bash shell (running inside screen) is receiving it. For example, for F1, it sends the following (hexdump is a perl script I wrote that takes STDIN in binmode and outputs it as a hexadecimal/ascii dump): % hexdump [press F1 and then hit ^D to terminate input] 00000000: 1b4f50 .OP If things were working correctly, I don't think bash should receive the escape sequence because screen should have caught it and turned it into a command. How do I get the function keys to work?

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• Observing events on injected elements using prototype

  - by snaken

  I asked a question previously, it was answered correctly in the form i asked it but realised now why it wasnt working for me. i have this code to observe multiple select menus: $('product_options').select('select').invoke("observe","change",optchange); This does work - as pointed out - with static layout like this: <html> <head> <title>optchange</title> <script type="text/javascript" src="prototype.js"></script> </head> <body> <div id="product_options"> <select id="o0"> <option>1</option> <option>2</option> </select> <select id="o1"> <option>1</option> <option>2</option> </select> <select id="o3"> <option>1</option> <option>2</option> </select> </div> <script type="text/javascript"> function optchange(e) { alert("optchanged"); } $('product_options').select('select').invoke("observe","change", optchange); </script> </body> </html> But in my context, making a selection in the first select menu fires of an Ajax.Updater that completely replaces the content of Select 2 - this is killing the event observer. Is there a way to fix this without having to apply a new event observer each time? Thanks.

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• how to do introspection in R (stat package)

  - by Lebron James

  Hi all, I am somewhat new to R, and i have this piece of code which generates a variable that i don't know the type for. Are there any introspection facility in R which will tell me which type this variable belongs to? The following illustrates the property of this variable: I am working on linear model selection, and the resource I have is lm result from another model. Now I want to retrieve the lm call by the command summary(model)$call so that I don't need to hardcode the model structure. However, since I have to change the dataset, I need to do a bit of modification on the "string", but apparently it is not a simple string. I wonder if there is any command similar to string.replace so that I can manipulate this variable from the variable $call. Thanks > str<-summary(rdnM)$call > str lm(formula = y ~ x1, data = rdndat) > str[1] lm() > str[2] y ~ x1() > str[3] rdndat() > str[3] <- data Warning message: In str[3] <- data : number of items to replace is not a multiple of replacement length > str lm(formula = y ~ x1, data = c(10, 20, 30, 40)) > str<-summary(rdnM)$call > str lm(formula = y ~ x1, data = rdndat) > str[3] <- 'data' > str lm(formula = y ~ x1, data = "data") > str<-summary(rdnM)$call > type str Error: unexpected symbol in "type str" >

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• Strange C++ performance difference?

  - by STingRaySC

  I just stumbled upon a change that seems to have counterintuitive performance ramifications. Can anyone provide a possible explanation for this behavior? Original code: for (int i = 0; i < ct; ++i) { // do some stuff... int iFreq = getFreq(i); double dFreq = iFreq; if (iFreq != 0) { // do some stuff with iFreq... // do some calculations with dFreq... } } While cleaning up this code during a "performance pass," I decided to move the definition of dFreq inside the if block, as it was only used inside the if. There are several calculations involving dFreq so I didn't eliminate it entirely as it does save the cost of multiple run-time conversions from int to double. I expected no performance difference, or if any at all, a negligible improvement. However, the perfomance decreased by nearly 10%. I have measured this many times, and this is indeed the only change I've made. The code snippet shown above executes inside a couple other loops. I get very consistent timings across runs and can definitely confirm that the change I'm describing decreases performance by ~10%. I would expect performance to increase because the int to double conversion would only occur when iFreq != 0. Chnaged code: for (int i = 0; i < ct; ++i) { // do some stuff... int iFreq = getFreq(i); if (iFreq != 0) { // do some stuff with iFreq... double dFreq = iFreq; // do some stuff with dFreq... } } Can anyone explain this? I am using VC++ 9.0 with /O2. I just want to understand what I'm not accounting for here.

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• Need advice on using Grails and Ajax to append to a div like in Rails

  - by Nate

  I'm just starting out in Grails and need some advice on using Ajax. I want to append some html to the bottom of a div inside a form. This is basically what I have: -form- -div id="listOfchildren"- childrow 1 input fields childrow 2 input fields childrow 3 input fields -/div- -form- -a-Add Child 4-/a- When I click on the "Add Child" I want to make an ajax call that results in a new childrow getting inserted into the "listOfchildren" div. So the document would look like this: -form- -div id="listOfchildren"- childrow 1 input fields childrow 2 input fields childrow 3 input fields childrow 4 input fields -/div- -form- -a-Add Child 5-/a- In Rails I would do something simple like this: render :update do |page| page.insert_html :bottom, "list_of_children", :partial = child_partial page.replace "add_link", :partial = 'add_link' end The previous code sends an javascript back to the browser with two commands. The first command tells the browser to append some html to the bottom of a div. The second command updates the "add link" counter. In grails I can only see how to replace an entire div (which would wipe out the user's existing input) and I don't see how I can call multiple functions from the ajax response. I can probably do this if I was to write some javascript functions in prototype or whatever, but I'd like to avoid that if there is a simpler way. Thanks! Nate

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• How do I develop browser plugins with cross-platform and cross-browser compatibility in mind?

  - by Schnapple

  My company currently has a product which relies on a custom, in-house ActiveX control. The technology it employs (TWAIN) is itself cross-platform by design, but our solution is obviously limited to Internet Explorer on Windows. Long term we would like to become cross-browser and cross-platform (i.e., support other browsers on Windows, support the Macintosh or Linux). Obviously if we wanted to support Firefox on Windows I would need to write a plugin for it. But if we wanted to support the Macintosh, how do I attack that? Is it possible to compile a version of the Firefox plugin that runs on the Mac? Would I be remiss to not also support Safari on the Mac? Are there any plugins which are cross-browser on a platform? (i.e., can any browsers run plugins for other browsers) Since TWAIN is so low-level to the operating system, I do not think Java would be a solution in any capacity, but I could be wrong. What do people generally do when they want to support multiple platforms with a process that will need to be cross-platform and cross-browser compatible?

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• Google Analytics API Authentication Speedup

  - by Paulo

  I'm using a Google Analytics API Class in PHP made by Doug Tan to retrieve Analytics data from a specific profile. Check the url here: http://code.google.com/intl/nl/apis/analytics/docs/gdata/gdataArticlesCode.html When you create a new instance of the class you can add the profile id, your google account + password, a daterange and whatever dimensions and metrics you want to pick up from analytics. For example i want to see how many people visited my website from different country's in 2009. //make a new instance from the class $ga = new GoogleAnalytics($email,$password); //website profile example id $ga->setProfile('ga:4329539'); //date range $ga->setDateRange('2010-02-01','2010-03-08'); //array to receive data from metrics and dimensions $array = $ga->getReport( array('dimensions'=>('ga:country'), 'metrics'=>('ga:visits'), 'sort'=>'-ga:visits' ) ); Now you know how this API class works, i'd like to adress my problem. Speed. It takes alot of time to retrieve multiple types of data from the analytics database, especially if you're building different arrays with different metrics/dimensions. How can i speed up this process? Is it possible to store all the possible data in a cache so i am able to retrieve the data without loading it over and over again?

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• How can I remove duplicate nodes in XQuery?

  - by Brabster

  I have an XML document I generate on the fly, and I need a function to eliminate any duplicate nodes from it. My function looks like: declare function local:start2() { let $data := local:scan_books() return <books>{$data}</books> }; Sample output is: <books> <book> <title>XML in 24 hours</title> <author>Some Guy</author> </book> <book> <title>XML in 24 hours</title> <author>Some Guy</author> </book> </books> I want just the one entry in my books root tag, and there are other tags, like say pamphlet in there too that need to have duplicates removed. Any ideas? Updated following comments. By unique nodes, I mean remove multiple occurrences of nodes that have the exact same content and structure.

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• Delete all rows that do not have the value: Criteria 1 or Criteria 2 or Criteria 3 in Column D --> Using VBA Macro for excel

  - by JDS

  I am new to Macro's/VBA and cannot seem to figure out how to do this action for multiple criteria. I am trying to Delete all rows that do not have the value: Identify Fail or Identify Success in Column D. I write the following code and it works for one criteria "Identify Fail": '***********************************************' Sub DeleteRows() 'Action 1 --> Delete all Rows without Identify Fail in column D' Application.ScreenUpdating = False For i = Range("D" & Rows.Count).End(xlUp).Row To 1 Step -1 If Range("D" & i).Value <> "Identify Fail" Then Rows(i).Delete shift:=xlUp Next i Application.ScreenUpdating = True End Sub '***********************************************' Once I try to add 'OR' with another criteria it does not work: '***********************************************' Sub DeleteRows() 'Action 1 --> Delete all Rows without Identify Fail in column D' Application.ScreenUpdating = False For i = Range("D" & Rows.Count).End(xlUp).Row To 1 Step -1 If Range("D" & i).Value <> "Identify Fail" Or "Identify Success" Then Rows(i).Deleteshift:=xlUp Next i Application.ScreenUpdating = True End Sub '***********************************************' Any suggestions would be appreciated as I have been scouring this website and have not found an efficient code that will do the trick.

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• Java/BlackBerry build error overriding too many classes

  - by behrk2

  Hey everyone, Has anyone ever heard of overriding too many classes in Java? Perhaps this issue is just related to BlackBerry development, but I was wondering if it is an issue in Java, too. Let's say I have the following: LabelField lblTitle = new LabelField(title) { protected void paint(Graphics graphics) { graphics.setColor(0x00FFFFFF); graphics.clear(); super.paint(graphics); } }; LabelField lblSubTitle = new LabelField(releaseYear + ", " + rating) { protected void paint(Graphics graphics) { graphics.setColor(0x00FFFFFF); graphics.clear(); super.paint(graphics); } }; This code works. However, I've noticed that by overriding the paint() method multiple times in many different classes throughout my project, I receive the error: I/O Error: Cannot run program "jar": CreateProcess error=2, The system cannot find the file specified My only solution thus far is to clean up my GUI code...minimize it and reuse it. Perhaps its good that this happened so I can be less careless about creating GUI code all over my classes. Anyways, I was just wondering if anyone has heard of this before. If you are interested in reading more about the issue I have been facing, check out the following link: BlackBerry Java Development Forums

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• Visual Studio expression containing a term named "by" cannot be evaluated in the watch window

  - by Andrei Pana

  Consider my C++ code below: int _tmain(int argc, _TCHAR* argv[]) { int by = 10; printf("%d\n", by); int bx = 20; printf("%d\n", (by + bx)); return 0; } which works fine. The funny thing is with the "by" variable. If I try to add a watch for a simple expression that contains by, the result will be CXX0030: Error: expression cannot be evaluated. For example, on a breakpoint on return 0, if I add the following watches I get the results mentioned: by : 10 bx : 20 by + 5 : CXX0030: Error: expression cannot be evaluated bx + 5 : 25 by + bx : CXX0030: Error: expression cannot be evaluated (by) + bx : 30 by + (bx) : CXX0030: Error: expression cannot be evaluated bx + (by) : CXX0014: Error: missing operrand This happens on VS2010, VS2008 on multiple computers. So, more out of curiosity, what is happening with "by"? Is it some kind of strange operator? Why doesn't bx get the same treatment? (I've tried google on this but it is quite difficult to get some relevant hits with terms like "by")

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• There's a black hole in my server (TcpClient, TcpListener)

  - by Matías

  Hi, I'm trying to build a server that will receive files sent by clients over a network. If the client decides to send one file at a time, there's no problem, I get the file as I expected, but if it tries to send more than one I only get the first one. Here's the server code: I'm using one Thread per connected client public void ProcessClients() { while (IsListening) { ClientHandler clientHandler = new ClientHandler(listener.AcceptTcpClient()); Thread thread = new Thread(new ThreadStart(clientHandler.Process)); thread.Start(); } } The following code is part of ClientHandler class public void Process() { while (client.Connected) { using (MemoryStream memStream = new MemoryStream()) { int read; while ((read = client.GetStream().Read(buffer, 0, buffer.Length)) > 0) { memStream.Write(buffer, 0, read); } if (memStream.Length > 0) { Packet receivedPacket = (Packet)Tools.Deserialize(memStream.ToArray()); File.WriteAllBytes(Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.DesktopDirectory), Guid.NewGuid() + receivedPacket.Filename), receivedPacket.Content); } } } } On the first iteration I get the first file sent, but after it I don't get anything. I've tried using a Thread.Sleep(1000) at the end of every iteration without any luck. On the other side I have this code (for clients) . . client.Connect(); foreach (var oneFilename in fileList) client.Upload(oneFilename); client.Disconnect(); . . The method Upload: public void Upload(string filename) { FileInfo fileInfo = new FileInfo(filename); Packet packet = new Packet() { Filename = fileInfo.Name, Content = File.ReadAllBytes(filename) }; byte[] serializedPacket = Tools.Serialize(packet); netStream.Write(serializedPacket, 0, serializedPacket.Length); netStream.Flush(); } netStream (NetworkStream) is opened on Connect method, and closed on Disconnect. Where's the black hole? Can I send multiple objects as I'm trying to do? Thanks for your time.

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• Dynamic Connection Strings for Strongly Typed DataSet in a Class Library using App.Config

  - by Luc

  This is my first question on StackOverflow.com and I'm not sure if this is the correct way to do this. I found a similar question titled: Modifying the Data Source for the Strongly Typed Dataset Connection String. However, the answer provided is not working for me. I'm not able to comment on it because I don't have enough "reputation points" (again, I just signed up), and I didn't want to provide an "answer", because I don't know the correct answer. My problem is that I need to be able to modify the connection string inside the generated myproject.dll.config file, but doing so has no effect for me at all. My library still uses the default connection string that was setup at design time. I've tried everything I know to try, but still no luck. I've tried working around the issue using multiple different approaches, but still the problem persists. I can't find any help on the internet with my specific problem either. It would be great if somebody could shed some light as to why my modified config file isn't being read. Useful information: I'm using a Strongly Typed DataSet I don't know the actual connection string at design time. The app.config doesn't allow me to specify a 'User' scoped connection string. I'm tied to a class library (no Windows Forms) Thank you for any help! Luc

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• How to get child container reference in View Model

  - by niels-verkaart

  Hello, I´m trying to share a Data Service (Entity Manager) wrapped in a Repository from a ViewModel (called 'AVM') in Module A to a ViewModel (called 'BVM') in Module B, and I can't get this working. We use PRISM/Unity 2.0 This is my scenario: A user may open multiple Customer screens (composite view as mini shell) each with another customer (unit of work). We realize this using child containers. Each child container resolves it's own repository with its own Entity manager (the repository is a singleton within the child container). This is done in module A. The main shell has a main region manager, and each Customer screen with its childcontainer creates a scoped region. In each customer screen there is a View 'AV' (connected to ViewModel 'AVM') with a SubRegion (tab control) registered as 'SubRegion'. We create this with a 'Screen Factory' In Module B we have a Customer Orders in View 'BV' and ViewModel 'BVM'. In the constructor of Module B we get the main container by injection. In the initialize method we resolve the (main) region manager and register View 'BV' with it. In the constructor of View 'BV' a ViewModel 'BVM' is injected/created. Now this works, but the ViewModel 'BVM' cannot get the child container. It only get the main container. Is this doable, or do I have to do this another way? Thanks, Niels

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• fixed layout in formview template

  - by Jeroen

  I have n pages with formviews, all sharing a similar layout inside their item/edit/insert templates. For example all item and edit templates have a header and body part inside where i put the fields. The header has a certain style and the body part too. My question is how can i enforce this style in all my formviews without repeating the same bulk css styles all the time. Now i'm using masterpages for this with multiple formviews on 1 page. That's not good i think. I want one 1 page for edit/insert/item and 1 formview. I would prefer somehow to define the style for edit template once and load it into every formview. Ofcourse not all the formviews have the same fields, so like masterpages i would like to have 'areas' where i can put my fields. The perfect way i suppose would be to have a formview span a complete masterpage based page including the contentplaceholders inside it's edit/insert/item templates. Any ideas are more than welcome. Edit: I read it's possible in .Net 4 using dynamic data. I'm stuck with 3.5 for the moment.

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• Using DPAPI / ProtectedData in a web farm environment with the User Store

  - by Lachman

  I was wondering if anyone had successfully used DPAPI with a user store in a web farm enviroment? Because our application is a recently converted from 1.1 to 2.0 asp.net app, we're using a custom wrapper which directly calls the CryptUnprotect methods. But this should be the same as the ProtectedData method available in the 2.0 framework. Because we are operating in a web farm environment, we can't guarantee that the machine that did the encryption is going to be the one decrypting it. (Also because machine failures shouldn't destroy our encrypted data). So what we have is a serviced component that runs in a service under a particular user account on each one of our web boxes. This user is a set up to have a roaming profile, as per the recomendation. The problem we have is that info encrypted on one machine can not be decrypted on another, this fails with the win32 error 'Key not valid for use in specified state'. I suspect that this is because I've made a mistake by having the encryption service running as the user on multiple machines, hence keeping the user logged in on more than one machine at the same time. If this is the problem, how are other using DPAPI with the User Store in a web farm environment?

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• Having trouble adding jquery to charisma

  - by kira423

  I am trying to add some jquery to this Charisma admin panel and have been having nothing but trouble. I am trying to add it to the charisma.js file. This is what I am adding // add multiple select / deselect functionality $("#selectall").click(function () { $('.checkbox').attr('checked', this.checked); }); // if all checkbox are selected, check the selectall checkbox // and viceversa $(".checkbox").click(function(){ if($(".checkbox").length == $(".checkbox:checked").length) { $("#selectall").attr("checked", "checked"); } else { $("#selectall").removeAttr("checked"); } }); I have tried this code wrapped in the anonymous $(function(){ as well as without, and I have inserted it into both $(document).ready(function(){ and docReady() as well as in the head of my code but I am not really "trained" on jquery so I am a bit lost as to what I am doing wrong. My class and div tags are correct for the code, as I have checked them several times for misspellings. I am not sure what I am doing wrong. Is there a better "check" all code I can use here, or am I just putting this all in the wrong place? UPDATE: I think the actual code may be working, I cannot tell, after I click the select all box it seems that I have to click the other boxes 3 times to get the check mark back into the box, so it seems like it is having trouble actually showing that the box is marked. This may be a problem with styling, but I don't know how to correct it.

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• detecting pauses in a spoken word audio file using pymad, pcm, vad, etc

  - by james

  First I am going to broadly state what I'm trying to do and ask for advice. Then I will explain my current approach and ask for answers to my current problems. Problem I have an MP3 file of a person speaking. I'd like to split it up into segments roughly corresponding to a sentence or phrase. (I'd do it manually, but we are talking hours of data.) If you have advice on how to do this programatically or for some existing utilities, I'd love to hear it. (I'm aware of voice activity detection and I've looked into it a bit, but I didn't see any freely available utilities.) Current Approach I thought the simplest thing would be to scan the MP3 at certain intervals and identify places where the average volume was below some threshold. Then I would use some existing utility to cut up the mp3 at those locations. I've been playing around with pymad and I believe that I've successfully extracted the PCM (pulse code modulation) data for each frame of the mp3. Now I am stuck because I can't really seem to wrap my head around how the PCM data translates to relative volume. I'm also aware of other complicating factors like multiple channels, big endian vs little, etc. Advice on how to map a group of pcm samples to relative volume would be key. Thanks!

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• Storing URLs while Spidering

  - by itemio

  I created a little web spider in python which I'm using to collect URLs. I'm not interested in the content. Right now I'm keeping all the visited URLs in a set in memory, because I don't want my spider to visit URLs twice. Of course that's a very limited way of accomplishing this. So what's the best way to keep track of my visited URLs? Should I use a database? * which one? MySQL, sqlite, postgre? * how should I save the URLs? As a primary key trying to insert every URL before visiting it? Or should I write them to a file? * one file? * multiple files? how should I design the file-structure? I'm sure there are books and a lot of papers on this or similar topics. Can you give me some advice what I should read?

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• should this database table be normalized?

  - by oo

  i have taken over a database that stores fitness information and we were having a debate about a certain table and whether it should stay as one table or get broken up into three tables. Today, there is one table called: workouts that has the following fields id, exercise_id, reps, weight, date, person_id So if i did 2 sets of 3 different exercises on one day, i would have 6 records in that table for that day. for example: id, exercise_id, reps, weight, date, person_id 1, 1, 10, 100, 1/1/2010, 10 2, 1, 10, 100, 1/1/2010, 10 3, 1, 10, 100, 1/1/2010, 10 4, 2, 10, 100, 1/1/2010, 10 5, 2, 10, 100, 1/1/2010, 10 6, 2, 10, 100, 1/1/2010, 10 So the question is, given that there is some redundant data (date, personid, exercise_id) in multiple records, should this be normalized to three tables WorkoutSummary: - id - date - person_id WorkoutExercise: - id - workout_id (foreign key into WorkoutSummary) - exercise_id WorkoutSets: - id - workout_exercise_id (foreign key into WorkoutExercise) - reps - weight I would guess the downside is that the queries would be slower after this refactoring as now we would need to join 3 tables to do the same query that had no joins before. The benefit of the refactoring allows up in the future to add new fields at the workout summary level or the exercise level with out adding in more duplication. any feedback on this debate?

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• Matplotlib canvas drawing

  - by Morgoth

  Let's say I define a few functions to do certain matplotlib actions, such as def dostuff(ax): ax.scatter([0.],[0.]) Now if I launch ipython, I can load these functions and start a new figure: In [1]: import matplotlib.pyplot as mpl In [2]: fig = mpl.figure() In [3]: ax = fig.add_subplot(1,1,1) In [4]: run functions # run the file with the above defined function If I now call dostuff, then the figure does not refresh: In [6]: dostuff(ax) I have to then explicitly run: In [7]: fig.canvas.draw() To get the canvas to draw. Now I can modify dostuff to be def dostuff(ax): ax.scatter([0.],[0.]) ax.get_figure().canvas.draw() This re-draws the canvas automatically. But now, say that I have the following code: def dostuff1(ax): ax.scatter([0.],[0.]) ax.get_figure().canvas.draw() def dostuff2(ax): ax.scatter([1.],[1.]) ax.get_figure().canvas.draw() def doboth(ax): dostuff1(ax) dostuff2(ax) ax.get_figure().canvas.draw() I can call each of these functions, and the canvas will be redrawn, but in the case of doboth(), it will get redrawn multiple times. My question is: how could I code this, such that the canvas.draw() only gets called once? In the above example it won't change much, but in more complex cases with tens of functions that can be called individually or grouped, the repeated drawing is much more obvious, and it would be nice to be able to avoid it. I thought of using decorators, but it doesn't look as though it would be simple. Any ideas?

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• custom C++ boost::lambda expression help

  - by aaa

  hello. A little bit of background: I have some strange multiple nested loops which I converted to flat work queue (basically collapse single index loops to single multi-index loop). right now each loop is hand coded. I am trying to generalized approach to work with any bounds using lambda expressions: For example: // RANGE(i,I,N) is basically a macro to generate `int i = I; i < N; ++i ` // for (RANGE(lb, N)) { // for (RANGE(jb, N)) { // for (RANGE(kb, max(lb, jb), N)) { // for (RANGE(ib, jb, kb+1)) { // is equivalent to something like (overload , to produce range) flat<1, 3, 2, 4>((_2, _3+1), (max(_4,_3), N), N, N) the internals of flat are something like: template<size_t I1, size_t I2, ..., class L1_, class L2, ..._> boost::array<int,4> flat(L1_ L1, L2_ L2, ...){ //boost::array<int,4> current; class variable bool advance; L2_ l2 = L2.bind(current); // bind current value to lambda { L1_ l1 = L1.bind(current); //bind current value to innermost lambda l1.next(); advance = !(l1 < l1.upper()); // some internal logic if (advance) { l2.next(); current[0] = l1.lower(); } } //..., } my question is, can you give me some ideas how to write lambda (derived from boost) which can be bound to index array reference to return upper, lower bounds according to lambda expression? thank you much

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