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  • Developer Preview of Java SE 8 for ARM Now Available

    - by Tori Wieldt
    A Developer Preview of Java SE 8 including JavaFX (JDK 8) on Linux for ARM processors is now available for immediate download from Java.net. As Java Evangelist Stephen Chin says, "This is a great platform for doing small embedded projects, a low cost computing system for teaching, and great fun for hobbyists." This Developer Preview is provided to the community so that you can provide us with valuable feedback on the ongoing progress of the project. We wanted to get this release out to you as quickly as we can so you can start using this build of Java SE 8 on an ARM device, such as the Raspberry Pi (http://raspberrypi.org/). Download JDK 8 for ARM Read the documentation for this early access release Let Us Know What You Think!Use the Forums to share your stories, comments and questions. Java SE Snapshots: Project Feedback Forum  JavaFX Forum We are interested in both problems and success stories. If something does not work or behaves differently than what you expect, please check the list of known issues and if yours is not listed there, then report a bug at JIRA Bug Tracking System. More ResourcesJavaFX on Raspberry Pi – 3 Easy Steps by Stephen Chin OTN Tech Article: Getting Started with Java SE Embedded on the Raspberry Pi by Bill Courington and Gary Collins Java Magazine Article: Getting Started with Java SE for Embedded Devices on Raspberry Pi (Free subscription required) Video: Quickie Guide Getting Java Embedded Running on Raspberry Pi by Hinkmond Wong 

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  • Don't Miss At Devoxx!!!

    - by Yolande Poirier
    Come by IoT Hack Fest which starts with the session: kickstart your Raspberry Pi and/or Leap Motion project, part II on Tuesday from 9:30am to 12:00pm to learn how to start a project with the Raspberry Pi and Leap Motion. In the afternoon, you can still join a project and create your own project with the help of experts on Raspberry Pi, Leap Motion and other boards.  At the Oracle booth, Java experts will be available  to answer your  questions and demo the new features of the Java Platform, including Java Embedded, JavaFX, Java SE and Java EE. This year, the chess game that was first demoed at JavaOne keynotes last September will be showcased at Devoxx.  Duke is coming to Devoxx this year. You can get your picture taken with Duke on Tuesday, Wednesday and Thursday (Nov. 12-14) from 12:00 to 18:00 Beer bash will be Tuesday from 17:30-19:30 and Wednesday/Thursday from 18:00 to 20:00 at the booth. Oracle is raffling off five Raspberry Pi's and a number of books every day. Make sure to stop by and get your badge scanned to enter the raffle. Raffles are Tuesday at 19:15 and Wednesday/Thursday at 19:45 at the Oracle booth.  The main conference sessions from Oracle Java experts are:  Wednesday 13 November Beyond Beauty: JavaFX, Parallax, Touch, Raspberry Pi, Gyroscopes, and Much More Angela Caicedo, Senior Member, Technical Staff, Oracle Room 7, 12:00–13:00 Lambda: A Peek Under the Hood, Brian Goetz, Software Architect, Oracle Room 8, 12:00–13:00 In Full Flow: Java 8 Lambdas in the Stream, Paul Sandoz, Software Developer, Oracle Room 8, 14:00–15:00 The Modular Java Platform and Project Jigsaw, Mark Reinhold, Chief Architect, Java Platform Group, Oracle, Room 8, 15:10–16:10 The Curious Case of JavaScript on the JVM, Attila Szegedi, Principal Member, Technical Staff, Oracle, Room 5, 16:40–17:40 Is It a Car? Is It a Computer? No, It’s a Raspberry Pi JavaFX Informatics System. Simon Ritter, Principal Technology Evangelist, Oracle Room 7, 16:40–17:40 Thursday 14 November Java EE 7: What’s New in the Java EE Platform Linda DeMichiel, Consulting Member, Technical Staff, Oracle, Room 8, 10:50–11:50 Java Microbenchmark Harness: The Lesser of the Two Evils, Aleksey Shipilev, Principal Member, Technical Staff, Oracle. Room 6, 14:00–15:00 Practical Restful Persistence, Shaun Smith, Senior Principal Product Manager, Oracle Room 8, 17:50–18:50 Friday 15 November Avatar.js, Server-Side JavaScript on the Java Platform, Jean-Francois Denise, Software Developer, Oracle Room 8, 11:50–12:50

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  • Simple collision detection for pong

    - by Dave Voyles
    I'm making a simple pong game, and things are great so far, but I have an odd bug which causes my ball (well, it's a box really) to get stuck on occasion when detecting collision against the ceiling or floor. It looks as though it is trying to update too frequently to get out of the collision check. Basically the box slides against the top or bottom of the screen from one paddle to the other, and quickly bounces on and off the wall while doing so, but only bounces a few pixels from the wall. What can I do to avoid this problem? It seems to occur at random. Below is my collision detection for the wall, as well as my update method for the ball. public void UpdatePosition() { size.X = (int)position.X; size.Y = (int)position.Y; position.X += speed * (float)Math.Cos(direction); position.Y += speed * (float)Math.Sin(direction); CheckWallHit(); } // Checks for collision with the ceiling or floor. // 2*Math.pi = 360 degrees // TODO: Change collision so that ball bounces from wall after getting caught private void CheckWallHit() { while (direction > 2 * Math.PI) { direction -= 2 * Math.PI; } while (direction < 0) { direction += 2 * Math.PI; } if (position.Y <= 0 || (position.Y > resetPos.Y * 2 - size.Height)) { direction = 2 * Math.PI - direction; } }

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  • Bounding volume hierarchy - linked nodes (linear model)

    - by teodron
    The scenario A chain of points: (Pi)i=0,N where Pi is linked to its direct neighbours (Pi-1 and Pi+1). The goal: perform efficient collision detection between any two, non-adjacent links: (PiPi+1) vs. (PjPj+1). The question: it's highly recommended in all works treating this subject of collision detection to use a broad phase and to implement it via a bounding volume hierarchy. For a chain made out of Pi nodes, it can look like this: I imagine the big blue sphere to contain all links, the green half of them, the reds a quarter and so on (the picture is not accurate, but it's there to help understand the question). What I do not understand is: How can such a hierarchy speed up computations between segments collision pairs if one has to update it for a deformable linear object such as a chain/wire/etc. each frame? More clearly, what is the actual principle of collision detection broad phases in this particular case/ how can it work when the actual computation of bounding spheres is in itself a time consuming task and has to be done (since the geometry changes) in each frame update? I think I am missing a key point - if we look at the picture where the chain is in a spiral pose, we see that most spheres are already contained within half of others or do intersect them.. it's odd if this is the way it should work.

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  • Hack Fest at Devoxx

    - by Yolande Poirier
    On November 11th and 12th, Devoxx attendees will get the chance to build a Java embedded application onsite. During the Raspberry Pi & Leap Motion hands-on labs on Monday and Tuesday mornings, you will learn about Raspberry Pi development with Java embedded using Leap Motion and other sensors. The afternoons are hacking time on a project of your choice. You can get your inspiration from existing projects. You can also use their project source code and improve on already developed applications.  The goal is for you to create something fun and innovative in only a couple of days, no matter your experience in embedded systems.  We provide you with equipment like the Raspberry Pi, sensors, and Leap Motion. Thanks to Stephan Janssen for lending us 10 Leap Motions for the Hack Fest. Raspberry Pi and sensors are pre-configured. You will access the sensors via a web address. You can build a project alone if you want. We also give the opportunity to brainstorm ideas with other attendees and maybe build something more complex. You will get one-on-one help from top-notch coaches. Vinicius Senger has tons of experience with Java and the Raspberry. He runs Java embedded challenges and give training year round. Geert Bevin contributed to many open source projects and his latest venture is with the Leap Motion. Bruno Borges's expertise is in connecting backend logic with great interfaces. Yara Senger is a Java Champion and a great Java embedded mentor.    Don't miss this opportunity! This is your chance to transform your idea into a Raspberry Pi or a Leap Motion application.

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  • What is the right approach when using STL container for median calculation?

    - by sharkin
    Let's say I need to retrieve the median from a sequence of 1000000 random numeric values. If using anything but STL::list, I have no (built-in) way to sort sequence for median calculation. If using STL::list, I can't randomly access values to retrieve middle (median) of sorted sequence. Is it better to implement sorting myself and go with e.g. STL::vector, or is it better to use STL::list and use STL::list::iterator to for-loop-walk to the median value? The latter seems less overheadish, but also feels more ugly.. Or are there more and better alternatives for me?

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  • Calculation with dates and different locales in Crystal Reports for Eclipse?

    - by Bevor
    Hello, I'm using Crystal Reports for Eclipse 2.0.4 and I have a problem. I use a formula in an report to subtract one day from a string which is a date: ToText(CDate({Agreement.EndDate})-1, "dd.MM.yyyy"); This works for the German locale. With an English locale, the calculation is absolutely wrong because the day and month is interchanged. For example: When {Agreement.EndDate} is 07.05.2010 and I subtract one day from it, I get 06.04.2010 with the German locale but 04.07.2010 with an English locale. How can I solve this that I works for different locales?

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  • Why does RunDLL32 process exit early on Windows 7?

    - by Vicky
    On Windows XP and Vista, I can run this code: STARTUPINFO si; PROCESS_INFORMATION pi; BOOL bResult = FALSE; ZeroMemory(&pi, sizeof(pi)); ZeroMemory(&si, sizeof(si)); si.cb = sizeof(STARTUPINFO); si.dwFlags = STARTF_USESHOWWINDOW; si.wShowWindow = SW_SHOW; bResult = CreateProcess(NULL, "rundll32.exe shell32.dll,Control_RunDLL modem.cpl", NULL, NULL, FALSE, NORMAL_PRIORITY_CLASS, NULL, NULL, &si, &pi); if (bResult) { WaitForSingleObject(pi.hProcess, INFINITE); CloseHandle(pi.hProcess); CloseHandle(pi.hThread); } and it operates as I would expect, i.e. the WaitForSingleObject does not return until the Modem Control Panel window has been closed by the user. On Windows 7, the same code, WaitForSingleObject returns straight away (with a return code of 0 indicating that the object signalled the requested state). Similarly, if I take it to the command line, on XP and Vista I can run start /wait rundll32.exe shell32.dll,Control_RunDLL modem.cpl and it does not return control to the command prompt until the Control Panel window is closed, but on Windows 7 it returns immediately. Is this a change in RunDll32? I know MS made some changes to RunDll32 in Windows 7 for UAC, and it looks from these experiments as though one of those changes might have involved spawning an additional process to display the window, and allowing the originating process to exit. The only thing that makes me think this might not be the case is that using a process explorer that shows the creation and destruction of processes, I do not see anything additional being created beyond the called rundll32 process itself. Any other way I can solve this? I just don't want the function to return until the control panel window is closed.

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  • CreateProcess() fails with an access violation

    - by John Doe
    My aim is to execute an external executable in my program. First, I used system() function, but I don't want the console to be seen to the user. So, I searched a bit, and found CreateProcess() function. However, when I try to pass a parameter to it, I don't know why, it fails. I took this code from MSDN, and changed a bit: #include <windows.h> #include <stdio.h> #include <tchar.h> void _tmain( int argc, TCHAR *argv[] ) { STARTUPINFO si; PROCESS_INFORMATION pi; ZeroMemory( &si, sizeof(si) ); si.cb = sizeof(si); ZeroMemory( &pi, sizeof(pi) ); /* if( argc != 2 ) { printf("Usage: %s [cmdline]\n", argv[0]); return; } */ // Start the child process. if( !CreateProcess( NULL, // No module name (use command line) L"c:\\users\\e\\desktop\\mspaint.exe", // Command line NULL, // Process handle not inheritable NULL, // Thread handle not inheritable FALSE, // Set handle inheritance to FALSE 0, // No creation flags NULL, // Use parent's environment block NULL, // Use parent's starting directory &si, // Pointer to STARTUPINFO structure &pi ) // Pointer to PROCESS_INFORMATION structure ) { printf( "CreateProcess failed (%d).\n", GetLastError() ); return; } // Wait until child process exits. WaitForSingleObject( pi.hProcess, INFINITE ); // Close process and thread handles. CloseHandle( pi.hProcess ); CloseHandle( pi.hThread ); } However, this code crated access violation somehow. Can I execute mspaint without showing user the console? Thank you very much.

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  • Using pair in c++

    - by user1543957
    Can someone please tell why i am unable to compile the following program #include<iostream> #include<string> #include<cmath> #include<iostream> #include<cfloat> #define MOD 10000009 using namespace std; double distance(pair<int,int> p1,pair<int,int> p2) { double dist; dist = sqrt( (p1.first-p2.first)*(p1.first-p2.first) + (p1.second-p2.second)*(p1.second-p2.second) ); return(dist); } int main() { int N,i,j; cin >> N; pair<int,int> pi[N]; for(i=0;i<N;i++) { cin >> pi[i].first >> pi[i].second; } for(i=0;i<N;i++) { cout << pi[i].first << " "<< pi[i].second << endl; } distance(pi[0],pi[1]); // This line is giving error return 0; }

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  • Web-app currency input/manipulation/calculation with javascript .. there has got to be a better (fra

    - by dreftymac
    BACKGROUND: I am of the "user-input-lockdown" school of thought. Whenever possible, I try to mistrust and sanitize user input, both client side and server side; and I try to take multiple opportunities to restrict possible inputs to a known subset of possibilities, usually this means providing a lot of checkboxes and select lists. (This is from the usability side of things, I know security-wise that malicious users can easily bypass fixed user input GUI controls). PROBLEM: Anyway, the problem always arises with non-fixed input of currency. Whenever I have to accept a freely-specified dollar amount as user input, I always have to confront these problems/annoyances and it is always painful: 1) Make sure to give the user two input boxes for each currency_datapoint, one for the whole_dollar_part and another for the fractional_pennies_part 2) Whenever the user changes a currency_datapoint, provide keystroke-by-keystroke GUI feedback to let them know whether the currency_datapoint is well-formed, with context-appropriate validation rules (e.g., no negatives?, nonzero only?, numeric only!, no non-numeric punctuation! no symbols!) 3) For display purposes, every user-provided currency_datapoint should be translated to human-readable currency formatting (dollar sign, period, commas provided by the app, where appropriate) 4) For calculation purposes, every user-provided currency_datapoint has to be converted to integer (all pennies, to avoid floating point errors) and summed into a grand total with zero or more subtotals. 5) Every user-provided currency_datapoint should be displayed or displayable in a nice "tabular" format, which auto-updates as the user enters each currency_datapoint, including a baloon that warns when one or more currency_datapoints is not well-formed. I seem to be re-inventing this wheel every time I have to work with currency in Javascript on the client side (server side is a bit more flexible since most programming languages have higher-level currency formatting logic). QUESTION: Has anyone out there solved the problem of dealing with the above issues, client side, in a way that is server-side-technology-stack agnostic, (preferrably plain javascript or jquery)? This is getting old, there has to be a better way.

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  • Naive Bayesian classification (spam filtering) - Doubt in one calculation? Which one is right? Plz c

    - by Microkernel
    Hi guys, I am implementing Naive Bayesian classifier for spam filtering. I have doubt on some calculation. Please clarify me what to do. Here is my question. In this method, you have to calculate P(S|W) - Probability that Message is spam given word W occurs in it. P(W|S) - Probability that word W occurs in a spam message. P(W|H) - Probability that word W occurs in a Ham message. So to calculate P(W|S), should I do (1) (Number of times W occuring in spam)/(total number of times W occurs in all the messages) OR (2) (Number of times word W occurs in Spam)/(Total number of words in the spam message) So, to calculate P(W|S), should I do (1) or (2)? (I thought it to be (2), but I am not sure, so plz clarify me) I am refering http://en.wikipedia.org/wiki/Bayesian_spam_filtering for the info by the way. I got to complete the implementation by this weekend :( Thanks and regards, MicroKernel :) @sth: Hmm... Shouldn't repeated occurrence of word 'W' increase a message's spam score? In the your approach it wouldn't, right?. Lets take a scenario and discuss... Lets say, we have 100 training messages, out of which 50 are spam and 50 are Ham. and say word_count of each message = 100. And lets say, in spam messages word W occurs 5 times in each message and word W occurs 1 time in Ham message. So total number of times W occuring in all the spam message = 5*50 = 250 times. And total number of times W occuring in all Ham messages = 1*50 = 50 times. Total occurance of W in all of the training messages = (250+50) = 300 times. So, in this scenario, how do u calculate P(W|S) and P(W|H) ? Naturally we should expect, P(W|S) P(W|H)??? right. Please share your thought...

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  • WPF FlowDocument: force calculation of height etc. "off screen"

    - by Lars
    My target: a DocumentPaginator which takes a FlowDocument with a table, which splits the table to fit the pagesize and repeat the header/footer (special tagged TableRowGroups) on every page. For splitting the table I have to know the heights of its rows. While building the FlowDocument-table by code, the height/width of the TableRows are 0 (of course). If I assign this document to a FlowDocumentScrollViewer (PageSize is set), the heights etc. are calculated. Is this possible without using an UI-bound object? Instantiating a FlowDocumentScrollViewer which is not bound to a window doesn't force the pagination/calculation of the heights. This is how I determine the height of a TableRow (which works perfectly for documents shown by a FlowDocumentScrollViewer): FlowDocument doc = BuildNewDocument(); // what is the scrollviewer doing with the FlowDocument? FlowDocumentScrollViewer dv = new FlowDocumentScrollViewer(); dv.Document = doc; dv.Arrange(new Rect(0, 0, 0, 0)); TableRowGroup dataRows = null; foreach (Block b in doc.Blocks) { if (b is Table) { Table t = b as Table; foreach (TableRowGroup g in t.RowGroups) { if ((g.Tag is String) && ((String)g.Tag == "dataRows")) { dataRows = g; break; } } } if (dataRows != null) break; } if (dataRows != null) { foreach (TableRow r in dataRows.Rows) { double maxCellHeight = 0.0; foreach (TableCell c in r.Cells) { Rect start = c.ElementStart.GetCharacterRect(LogicalDirection.Forward); Rect end = c.ElementEnd.GetNextInsertionPosition(LogicalDirection.Backward).GetCharacterRect(LogicalDirection.Forward); double cellHeight = end.Bottom - start.Top; if (cellHeight > maxCellHeight) maxCellHeight = cellHeight; } System.Diagnostics.Trace.WriteLine("row " + dataRows.Rows.IndexOf(r) + " = " + maxCellHeight); } } Edit: I added the FlowDocumentScrollViewer to my example. The call of "Arrange" forces the FlowDocument to calculate its heights etc. I would like to know, what the FlowDocumentScrollViewer is doing with the FlowDocument, so I can do it without the UIElement. Is it possible?

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  • Processes Allocation in .Net

    - by mayap
    I'm writing some program which should perform calculations concurrently according to inputs which reach the system all the time. I'm considering 2 approaches to allocate "calculation" processes: Allocating processes in the system initialization, insert the ids to Processes table, and each time I want to perform calculation, I will check in the table which process is free. The questions: can I be sure that those processes are only for my use and that the operating system doesn't use them? Not allocating processes in advance. Each time when calculation should be done ask the operating system for free process. I need to know the following inputs from a "calculation" process: When calculation is finished and also if it succeeded or failed If a processes has failed I need to assign the calculation to another process Thanks in advance. Any help would be appreciated.

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  • Declare Locally or Globally in Delphi?

    - by lkessler
    I have a procedure my program calls tens of thousands of times that uses a generic structure like this: procedure PrintIndiEntry(JumpID: string); type TPeopleIncluded = record IndiPtr: pointer; Relationship: string; end; var PeopleIncluded: TList<TPeopleIncluded>; PI: TPeopleIncluded; begin { PrintIndiEntry } PeopleIncluded := TList<TPeopleIncluded>.Create; { A loop here that determines a small number (up to 100) people to process } while ... do begin PI.IndiPtr := ...; PI.Relationship := ...; PeopleIncluded.Add(PI); end; DoSomeProcess(PeopleIncluded); PeopleIncluded.Clear; PeopleIncluded.Free; end { PrintIndiEntry } Alternatively, I can declare PeopleIncluded globally rather than locally as follows: unit process; interface type TPeopleIncluded = record IndiPtr: pointer; Relationship: string; end; var PeopleIncluded: TList<TPeopleIncluded>; PI: TPeopleIncluded; procedure PrintIndiEntry(JumpID: string); begin { PrintIndiEntry } { A loop here that determines a small number (up to 100) people to process } while ... do begin PI.IndiPtr := ...; PI.Relationship := ...; PeopleIncluded.Add(PI); end; DoSomeProcess(PeopleIncluded); PeopleIncluded.Clear; end { PrintIndiEntry } procedure InitializeProcessing; begin PeopleIncluded := TList<TPeopleIncluded>.Create; end; procedure FinalizeProcessing; begin PeopleIncluded.Free; end; My question is whether in this situation it is better to declare PeopleIncluded globally rather than locally. I know the theory is to define locally whenever possible, but I would like to know if there are any issues to worry about with regards to doing tens of thousands of of "create"s and "free"s? Making them global will do only one create and one free. What is the recommended method to use in this case? If the recommended method is to still define it locally, then I'm wondering if there are any situations where it is better to define globally when defining locally is still an option.

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  • SSAS: Using fake dimension and scopes for dynamic ranges

    - by DigiMortal
    In one of my BI projects I needed to find count of objects in income range. Usual solution with range dimension was useless because range where object belongs changes in time. These ranges depend on calculation that is done over incomes measure so I had really no option to use some classic solution. Thanks to SSAS forums I got my problem solved and here is the solution. The problem – how to create dynamic ranges? I have two dimensions in SSAS cube: one for invoices related to objects rent and the other for objects. There is measure that sums invoice totals and two calculations. One of these calculations performs some computations based on object income and some other object attributes. Second calculation uses first one to define income ranges where object belongs. What I need is query that returns me how much objects there are in each group. I cannot use dimension for range because on one date object may belong to one range and two days later to another income range. By example, if object is not rented out for two days it makes no money and it’s income stays the same as before. If object is rented out after two days it makes some income and this income may move it to another income range. Solution – fake dimension and scopes Thanks to Gerhard Brueckl from pmOne I got everything work fine after some struggling with BI Studio. The original discussion he pointed out can be found from SSAS official forums thread Create a banding dimension that groups by a calculated measure. Solution was pretty simple by nature – we have to define fake dimension for our range and use scopes to assign values for object count measure. Object count measure is primitive – it just counts objects and that’s it. We will use it to find out how many objects belong to one or another range. We also need table for fake ranges and we have to fill it with ranges used in ranges calculation. After creating the table and filling it with ranges we can add fake range dimension to our cube. Let’s see now how to solve the problem step-by-step. Solving the problem Suppose you have ranges calculation defined like this: CASE WHEN [Measures].[ComplexCalc] < 0 THEN 'Below 0'WHEN [Measures].[ComplexCalc] >=0 AND  [Measures].[ComplexCalc] <=50 THEN '0 - 50'...END Let’s create now new table to our analysis database and name it as FakeIncomeRange. Here is the definition for table: CREATE TABLE [FakeIncomeRange] (     [range_id] [int] IDENTITY(1,1) NOT NULL,     [range_name] [nvarchar](50) NOT NULL,     CONSTRAINT [pk_fake_income_range] PRIMARY KEY CLUSTERED      (         [range_id] ASC     ) ) Don’t forget to fill this table with range labels you are using in ranges calculation. To use ranges from table we have to add this table to our data source view and create new dimension. We cannot bind this table to other tables but we have to leave it like it is. Our dimension has two attributes: ID and Name. The next thing to create is calculation that returns objects count. This calculation is also fake because we override it’s values for all ranges later. Objects count measure can be defined as calculation like this: COUNT([Object].[Object].[Object].members) Now comes the most crucial part of our solution – defining the scopes. Based on data used in this posting we have to define scope for each of our ranges. Here is the example for first range. SCOPE([FakeIncomeRange].[Name].&[Below 0], [Measures].[ObjectCount])     This=COUNT(            FILTER(                [Object].[Object].[Object].members,                 [Measures].[ComplexCalc] < 0          )     ) END SCOPE To get these scopes defined in cube we need MDX script blocks for each line given here. Take a look at the screenshot to get better idea what I mean. This example is given from SQL Server books online to avoid conflicts with NDA. :) From previous example the lines (MDX scripts) are: Line starting with SCOPE Block for This = Line with END SCOPE And now it is time to deploy and process our cube. Although you may see examples where there are semicolons in the end of statements you don’t need them. Visual Studio BI tools generate separate command from each script block so you don’t need to worry about it.

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  • Weird behavior of substitution in Mathematica.

    - by Ilya
    My question is: why doesn't the following work, and how do I fix it? Plot[f[t], {t, 0, 2*Pi}] /. {{f -> Sin}, {f -> Cos}} The result is two blank graphs. By comparison, DummyFunction[f[t], {t, 0, 2*Pi}] /. {{f -> Sin}, {f -> Cos}} gives {DummyFunction[Sin[t], {t, 0, 2 *Pi}], DummyFunction[Cos[t], {t, 0, 2 * Pi}]} as desired. This is a simplified version of what I was actually doing. I was very annoyed that, even after figuring out the annoying "right way" of putting the curly brackets nothing works. In the end, I did the following, which works: p[f_] := Plot[f[t], {t, 0, 2*Pi}] p[Sin] p[Cos]

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  • Start Default Browser - Windows

    - by dbasnett
    When starting the default browser like this: Dim trgt1 As String = "http://www.vbforums.com/showthread.php?t=612471" pi.FileName = trgt1 System.Diagnostics.Process.Start(pi) It takes about 40 seconds to open the page. If I do it like this, though this isn't the default browser Dim trgt1 As String = "http://www.vbforums.com/showthread.php?t=612471" pi.Arguments = trgt1 pi.FileName = "iexplore.exe" 'or firefox.exe System.Diagnostics.Process.Start(pi) it opens immediately. Is this a bug or a feature? I have tried this with both IE and FireFox set to be the default browser.

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  • How can I further optimize this color difference function?

    - by aLfa
    I have made this function to calculate color differences in the CIE Lab colorspace, but it lacks speed. Since I'm not a Java expert, I wonder if any Java guru around has some tips that can improve the speed here. The code is based on the matlab function mentioned in the comment block. /** * Compute the CIEDE2000 color-difference between the sample color with * CIELab coordinates 'sample' and a standard color with CIELab coordinates * 'std' * * Based on the article: * "The CIEDE2000 Color-Difference Formula: Implementation Notes, * Supplementary Test Data, and Mathematical Observations,", G. Sharma, * W. Wu, E. N. Dalal, submitted to Color Research and Application, * January 2004. * available at http://www.ece.rochester.edu/~gsharma/ciede2000/ */ public static double deltaE2000(double[] lab1, double[] lab2) { double L1 = lab1[0]; double a1 = lab1[1]; double b1 = lab1[2]; double L2 = lab2[0]; double a2 = lab2[1]; double b2 = lab2[2]; // Cab = sqrt(a^2 + b^2) double Cab1 = Math.sqrt(a1 * a1 + b1 * b1); double Cab2 = Math.sqrt(a2 * a2 + b2 * b2); // CabAvg = (Cab1 + Cab2) / 2 double CabAvg = (Cab1 + Cab2) / 2; // G = 1 + (1 - sqrt((CabAvg^7) / (CabAvg^7 + 25^7))) / 2 double CabAvg7 = Math.pow(CabAvg, 7); double G = 1 + (1 - Math.sqrt(CabAvg7 / (CabAvg7 + 6103515625.0))) / 2; // ap = G * a double ap1 = G * a1; double ap2 = G * a2; // Cp = sqrt(ap^2 + b^2) double Cp1 = Math.sqrt(ap1 * ap1 + b1 * b1); double Cp2 = Math.sqrt(ap2 * ap2 + b2 * b2); // CpProd = (Cp1 * Cp2) double CpProd = Cp1 * Cp2; // hp1 = atan2(b1, ap1) double hp1 = Math.atan2(b1, ap1); // ensure hue is between 0 and 2pi if (hp1 < 0) { // hp1 = hp1 + 2pi hp1 += 6.283185307179586476925286766559; } // hp2 = atan2(b2, ap2) double hp2 = Math.atan2(b2, ap2); // ensure hue is between 0 and 2pi if (hp2 < 0) { // hp2 = hp2 + 2pi hp2 += 6.283185307179586476925286766559; } // dL = L2 - L1 double dL = L2 - L1; // dC = Cp2 - Cp1 double dC = Cp2 - Cp1; // computation of hue difference double dhp = 0.0; // set hue difference to zero if the product of chromas is zero if (CpProd != 0) { // dhp = hp2 - hp1 dhp = hp2 - hp1; if (dhp > Math.PI) { // dhp = dhp - 2pi dhp -= 6.283185307179586476925286766559; } else if (dhp < -Math.PI) { // dhp = dhp + 2pi dhp += 6.283185307179586476925286766559; } } // dH = 2 * sqrt(CpProd) * sin(dhp / 2) double dH = 2 * Math.sqrt(CpProd) * Math.sin(dhp / 2); // weighting functions // Lp = (L1 + L2) / 2 - 50 double Lp = (L1 + L2) / 2 - 50; // Cp = (Cp1 + Cp2) / 2 double Cp = (Cp1 + Cp2) / 2; // average hue computation // hp = (hp1 + hp2) / 2 double hp = (hp1 + hp2) / 2; // identify positions for which abs hue diff exceeds 180 degrees if (Math.abs(hp1 - hp2) > Math.PI) { // hp = hp - pi hp -= Math.PI; } // ensure hue is between 0 and 2pi if (hp < 0) { // hp = hp + 2pi hp += 6.283185307179586476925286766559; } // LpSqr = Lp^2 double LpSqr = Lp * Lp; // Sl = 1 + 0.015 * LpSqr / sqrt(20 + LpSqr) double Sl = 1 + 0.015 * LpSqr / Math.sqrt(20 + LpSqr); // Sc = 1 + 0.045 * Cp double Sc = 1 + 0.045 * Cp; // T = 1 - 0.17 * cos(hp - pi / 6) + // + 0.24 * cos(2 * hp) + // + 0.32 * cos(3 * hp + pi / 30) - // - 0.20 * cos(4 * hp - 63 * pi / 180) double hphp = hp + hp; double T = 1 - 0.17 * Math.cos(hp - 0.52359877559829887307710723054658) + 0.24 * Math.cos(hphp) + 0.32 * Math.cos(hphp + hp + 0.10471975511965977461542144610932) - 0.20 * Math.cos(hphp + hphp - 1.0995574287564276334619251841478); // Sh = 1 + 0.015 * Cp * T double Sh = 1 + 0.015 * Cp * T; // deltaThetaRad = (pi / 3) * e^-(36 / (5 * pi) * hp - 11)^2 double powerBase = hp - 4.799655442984406; double deltaThetaRad = 1.0471975511965977461542144610932 * Math.exp(-5.25249016001879 * powerBase * powerBase); // Rc = 2 * sqrt((Cp^7) / (Cp^7 + 25^7)) double Cp7 = Math.pow(Cp, 7); double Rc = 2 * Math.sqrt(Cp7 / (Cp7 + 6103515625.0)); // RT = -sin(delthetarad) * Rc double RT = -Math.sin(deltaThetaRad) * Rc; // de00 = sqrt((dL / Sl)^2 + (dC / Sc)^2 + (dH / Sh)^2 + RT * (dC / Sc) * (dH / Sh)) double dLSl = dL / Sl; double dCSc = dC / Sc; double dHSh = dH / Sh; return Math.sqrt(dLSl * dLSl + dCSc * dCSc + dHSh * dHSh + RT * dCSc * dHSh); }

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  • Java Math.cos() Method Does Not Return 0 When Expected

    - by dimo414
    Using Java on a Windows 7 PC (not sure if that matters) and calling Math.cos() on values that should return 0 (like pi/2) instead returns small values, but small values that, unless I'm misunderstanding, are much greater than 1 ulp off from zero. Math.cos(Math.PI/2) = 6.123233995736766E-17 Math.ulp(Math.cos(Math.PI/2)) = 1.232595164407831E-32 Is this in fact within 1 ulp and I'm simply confused? And would this be an acceptable wrapper method to resolve this minor inaccuracy? public static double cos(double a){ double temp = Math.abs(a % Math.PI); if(temp == Math.PI/2) return 0; return Math.cos(a); }

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  • i'm trying to solve an equation using gfortran but i keep getting error

    - by sameon
    i'm using the below program but i keep getting error.What is wrong with my progam? real x complex y real m1,H0,Ms,P1,P2,P3,w0,wm,wh complex w1,w2,o1,o2 integer i,n real pi n=4000000000 pi=4*atan(1.0) m1=4*pi*1e-7 H0=39.79e3 Ms=1400e3 P1=0.7*0.12 P2=0.3*0.12 P3=P1-P2 w0=m1*(1.76e11)*H0 wm=m1*(1.76e11)*Ms wh=w0-P3*wm im=cmplx(0,1) w1=wm/2+wh-im*0.06*2*pi*x w2=wm/2-wh-im*0.06*2*pi*x o1=x**2-x*(2*wh-(P3*wm)/2)-w1*w2+(wm/2)*(P1*w2+P2*w1) o2=x**2+x*(2*wh-(P3*wm)/2)-w1*w2+(wm/2)*(P1*w2+P2*w1) do i=0,n x=i y=1+wm*(P1*w1*((w2)**2-x**2))/(o1*o2) & +wm*(P2*w2*((w1)**2-x**2))/(o1*o2) & -wm*((wm/2)*((P1*w2+P2*w1)**2)))/(o1*o2) & +wm*((wm/2)*((P3*x)**2))/(o1*o2) write(10,*)x,y enddo return end

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  • How to speed up calculation of length of longest common substring?

    - by eSKay
    I have two very large strings and I am trying to find out their Longest Common Substring. One way is using suffix trees (supposed to have a very good complexity, though a complex implementation), and the another is the dynamic programming method (both are mentioned on the Wikipedia page linked above). Using dynamic programming The problem is that the dynamic programming method has a huge running time (complexity is O(n*m), where n and m are lengths of the two strings). What I want to know (before jumping to implement suffix trees): Is it possible to speed up the algorithm if I only want to know the length of the common substring (and not the common substring itself)?

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  • How to keep , instead of . and how to make % form calculation need to be times 100

    - by rockers
    in my database table i have filed called Value.. its showing somethign like.. 1234231.23 but I need to dispaly this as , all currency values should include commas when appropriate such as after the millions and thousands digits.. This is the filed I am getting from data base.. value= !dr.IsDBNull(3) ? dr.GetDecimal(3) : new decimal(), and I need to chnage other value as % times 100.. i am gettnig from data base something liek this -021222 i need to display -2.1222% Percentage= !dr.IsDBNull(4) ? dr.GetDecimal(4) : new decimal(), Can I change in the my class? public decimal value { get;set;} public decimal Percentage {get;set;}

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