Search Results

Search found 3080 results on 124 pages for 'leon kaihua li'.

Page 63/124 | < Previous Page | 59 60 61 62 63 64 65 66 67 68 69 70  | Next Page >

  • misleading plot issue in mathematica

    - by Qiang Li
    I want to study some "strange" functions by plotting them out in mathematica. One example is the following: mod2[x_] := Which[Mod[x, 2] >= 1, -2 + Mod[x, 2], True, Mod[x, 2]]; f[x_] := Which[-1 <= x <= 1, Abs[x], True, Abs[mod2[x]]]; fn[x_, n_] := Sum[(3/4)^i*f[4^n*x], {i, 0, n}] Plot[{fn[x, 0], fn[x, 1], fn[x, 2], fn[x, 5]}, {x, -2, 2}] However, the plot I got from mma is misleading, in the sense that the maxima and minima of fn[x, 5] should be on the same two levels. But due to high oscillation of the function, and the fact that clearly mma only takes limited number of points to draw the function, you see the plot exhibit strange behavior. Is there any option in plot to remedy for this? Many thanks.

    Read the article

  • How to read from multiple queues in real-world?

    - by Leon Cullens
    Here's a theoretical question: When I'm building an application using message queueing, I'm going to need multiple queues support different data types for different purposes. Let's assume I have 20 queues (e.g. one to create new users, one to process new orders, one to edit user settings, etc.). I'm going to deploy this to Windows Azure using the 'minimum' of 1 web role and 1 worker role. How does one read from all those 20 queues in a proper way? This is what I had in mind, but I have little or no real-world practical experience with this: Create a class that spawns 20 threads in the worker role 'main' class. Let each of these threads execute a method to poll a different queue, and let all those threads sleep between each poll (of course with a back-off mechanism that increases the sleep time). This leads to have 20 threads (or 21?), and 20 queues that are being actively polled, resulting in a lot of wasted messages (each time you poll an empty queue it's being billed as a message). How do you solve this problem?

    Read the article

  • How to solve recursion relations in mathematica efficiently?

    - by Qiang Li
    I have a recursion to solve for. f(m,n)=Sum[f[m - 1, n - 1 - i] + f[m - 3, n - 5 - i], {i, 2, n - 2*m + 2}] + f[m - 1, n - 3] + f[m - 3, n - 7] f(0,n)=1, f(1,n)=n However, the following mma code is very inefficient f[m_, n_] := Module[{}, If[m < 0, Return[0];]; If[m == 0, Return[1];]; If[m == 1, Return[n];]; Return[Sum[f[m - 1, n - 1 - i] + f[m - 3, n - 5 - i], {i, 2, n - 2*m + 2}] + f[m - 1, n - 3] + f[m - 3, n - 7]];] It takes unbearably long to compute f[40,20]. Could anyone please suggest an efficient way of doing this? Many thanks!

    Read the article

  • how to use sort function the same way as max or min in mathematica

    - by Qiang Li
    Please take a look at the following code: Sort[{1, y, x}, Greater] Max[{1, x, y}] x = 1 y = 2 Sort[{1, y, x}, Greater] Max[{1, x, y}] It is interesting to note that the first Sort always produce a definite result while the first Max does not, even when Greater is specified. Note I have not given any numerical values for x and y. Why is this and how can I have a Sort function behave the same way as the Max (or Min) function? Thanks!

    Read the article

  • What version of Visual Studio is this python compiled with?

    - by leon
    I am trying to find out the version of Visual Study that is used to compile the python on my computer It says Python 2.6.2 (r262:71605, Apr 14 2009, 22:40:02) [MSC v.1500 32 bit (Intel)] on win32 What I do not understand is that MSC V.1500. Does it mean it is compiled with 2005? I cannot find this information on `python.org' neither. Any help is appreciated!

    Read the article

  • when to use "willChangeValueForKey" and "didChangeValueForKey"?

    - by Frost Li
    I saw these lines in a demo project, but I couldn't understand why it did that. [self willChangeValueForKey:@"names"]; [self didChangeValueForKey:@"names"]; It called didChangeValueForKey immediately after willChangeeValueForKey. Does it make any sense? Furthermore, when should be the right time to call this two methods? Thanks a lot!! :)

    Read the article

  • Open source live message plugin wanted

    - by Bill Li
    I need write a live messenger plugin which periodically read messages from a remote http server, and then change my signature(the short message after my name) accordingly. Can anyone point me to any open source project or materials where I can get started? Thanks.

    Read the article

  • R: Change the fields' (slots') values of the class assigning a value to some other field

    - by Max Li
    Assgning a value to one field, how can I make the other fields changing. Consider the following R5 class C<-setRefClass("C", fields=list(a="numeric",b="numeric") , methods=list( seta = function(x){ a<<-x b<<-x+10 cat("The change took place!") } ) # end of the methods list ) # end of the class Now create the instance of the class c<-C$new() This command c$seta(10) will result in that c$a is 10 and c$b is 20. So it actually works, however, I want to achieve this result by the command c$a<-10 (i.e. after that I want c$b to be equal to 20 as defined in the class in the logic of seta() function) How can I do it?

    Read the article

  • merging indexed array in Python

    - by leon
    Suppose that I have two numpy arrays of the form x = [[1,2] [2,4] [3,6] [4,NaN] [5,10]] y = [[0,-5] [1,0] [2,5] [5,20] [6,25]] is there an efficient way to merge them such that I have xmy = [[0, NaN, -5 ] [1, 2, 0 ] [2, 4, 5 ] [3, 6, NaN] [4, NaN, NaN] [5, 10, 20 ] [6, NaN, 25 ] I can implement a simple function using search to find the index but this is not elegant and potentially inefficient for a lot of arrays and large dimensions. Any pointer is appreciated.

    Read the article

  • Magento - how to create different prices for different sizes of a products?

    - by Lisa Li
    Hi, I am trying to set different prices for different sizes of a few products I have in my store. I am not really sure how to do that propely. The problem is that I already have the regular size defined as a simple product. Now, I want to add a smaller size as well, that can be chosen from the same product page, and I need to set the weight of the smaller size, so postage is calculated properly. Any suggestions? Many thanks!

    Read the article

  • Questions regarding Web Service development in C++

    - by Eduardo León
    The purpose of this question is to play a joke, but the question itself is serious. Inspired by DOS on Dope, I want to make my own framework for Web Service development based on MFC serialization. However, my only experience in Web Service development consists in having written a toy ASP.NET Web Service. All I had to do to expose a method was... [WebMethod] public ReturnType ExposedMethod(InputType1 param1, InputType2 param2) { //... } ... and ASP.NET took care of the rest for me. Obviously, I will have to do everything by hand in my own framework. Thus, I would like to delve a bit more into the little details of how ordinary SOAP Web Services work, in order to replicate them. So I have mainly two questions: Where can I find the details on how SOAP Web Services work, and what ASP.NET hides from me? What are the main challenges I am going to find in my completely lunatic project?

    Read the article

  • Array of an array (Database)

    - by Anne Mah Li'en
    I am trying to print out an array of an array from database Below are my codes. I am able to retrieve all the values from the first array. But error occurs when I am trying to retrieve the 2nd array from database. <% ArrayList<Questionnaire> allCategories =QuestionnaireController.getQuestionnaireByCategoryAll(); for(int i=0;i<allCategories.size();i++){ Questionnaire allCategoriesQuestionnaire=allCategories.get(i); out.println("<div class=\"silverheader\">" + "<a href= \"\">" + allCategoriesQuestionnaire.getCategory() + "</a>" + "</div>" + "<div class=\"submenu\">" + "ArrayList<Questionnaire> CategoriesSustainability =QuestionnaireController.getQuestionnaireByCategorySustainability();" + out.println(CategoriesSustainability.get(0).getCategory()); + "<br />" + "</div>"); } %>

    Read the article

  • How to make a piece of WPF content take up the entire application window

    - by Bojin Li
    I'm working on an application that contains a number of content areas. I want to implement a behavior such that in response to user input, any of these content areas can be toggled to fit the entire application window, and optionally back to its original position again. I experimented with several approaches and none of them seem optimal for me. Here's what I tried to do: Use the ClipToBoundsProperty on the content I want to make "Full Screen": Doesn't work because only the CanvasPanel seems to fully respect this property. The application need to be localized so I would really like to avoid the CanvasPanel. Use a Grid and collapse the other content areas, such that only the one I want to see is visible, hence taking up the entire screen: This will probably work but doesn't seem easy to implement nor maintain. The "Full Screen" content area could be several levels deep, for example residing inside a Tabcontrol, so I would have to hide the tab headers too etc. Reconstruct the content area in a separate view and display it while hiding the rest: Seems easy enough to do with DataTemplates and my ViewModel objects, but any GUI/View only states are not preserved using this approach. Somehow "lift" the GUI/View I want to "Full Screen" into the separate view and display it while hiding the rest: I don't know how to do this or even if this is possible. Anyway if anyone knows a better approach I would love to know about it. Thanks a lot!

    Read the article

  • UIView viewWithTag 0 problem

    - by leon
    Hi, On view in IB I have numerous items (including view itself). ONLY one item has tag 0, yet following line works for ANY UITextBox other then the one with tag 0. Note that only ONE UITextBox has tag 0, why: (UITextField *) [self.view viewWithTag:0]).text = @"foo"; Interesting that when triggered event received for the element with tag 0, I can get value of Tag 0 with no problem. Is there a limitation to look for tag 0 elements?

    Read the article

  • Modify an MP3 slightly to change the data appearence

    - by Léon Pelletier
    I'm thinking about encrypting MP3s in a database, so that when user is downloading them with his software desktop player, only the software can decrypt them. This part is not a problem. The problem is I don't want a user to upload an mp3 to the database, then check which changes have been made to the file so he can reverse-engineer the file or at least see which algorithm is used to encrypt the files. So, user uploads MP3-A, then it becomes MP3-B because it has been modified, and I encrypt it to MP3-C. And when decrypted, it sounds 99.99% like MP3-A. I know MP3 format is lossy, but I wonder if there's a way to convert audio with limited loss, or if I need to forget it right now.

    Read the article

  • Running the script for the 2-nd time, the messages are not retrieved from the mail server

    - by Max Li
    I read the mails from my gmail account with the code following below. import poplib pop_conn = poplib.POP3_SSL('pop.gmail.com') pop_conn.user('user') # result: '+OK send PASS' pop_conn.pass_('password') # result: '+OK Welcome.' print pop_conn.list()[1] pop_conn.quit() It shows me 1 message as expected. However, if I run this script for the second time, I get 0 messages as result. On the server the message is still there and unread. How can I get all the messages also running the script for the second time? For me it behaves as an email client that doesn't download the same mail twice. Is there some flag to force the program to download everything again? I use python 2.7.x on ubuntu 12.10

    Read the article

  • chrome.tab.onactivated

    - by Leon Cunningham
    Can someone please show me how to use the chrome.tabs.onActivated. I would like to refresh the tab that is clicked/activated if the url equals: www.example.com. Or if this is the wrong method please tell me what to use. Can someone please show me how to use the chrome.tabs.onActivated. I would like to refresh the tab that is clicked/activated if the url equals: www.example.com. Or if this is the wrong method please tell me what to use.

    Read the article

< Previous Page | 59 60 61 62 63 64 65 66 67 68 69 70  | Next Page >