Search Results

Search found 32961 results on 1319 pages for 'java'.

Page 916/1319 | < Previous Page | 912 913 914 915 916 917 918 919 920 921 922 923  | Next Page >

  • Getting Frequency Components with FFT

    - by ruhig brauner
    so I was able to solv my last problem but i stubmled upon the next already. So I want to make a simple spectrogram but in oder to do so I want to understand how FFT-libaries work and what they actually calculate and return. (FFT and Signal Processing is the number 1 topic I will get into as soon as I have time but right now, I only have time for some programming exercises in the evening. ;) ) Here I just summarized the most important parts: int framesPerSecond; int samplesPerSecond; int samplesPerCycle; // right now i want to refresh the spectogram every DoubleFFT_1D fft; WAVReader audioIn; double audioL[], audioR[]; double fftL[], fftR[]; ..... framesPerSecond = 30; audioIn= new WAVReader("Strobe.wav"); int samplesPerSecond = (int)audioIn.GetSampleRate(); samplesPerCycle = (int)(audioIn.GetSampleRate()/framesPerSecond); audioL = new double[samplesPerCycle*2]; audioR = new double[samplesPerCycle*2]; fftL = new double[samplesPerCycle]; fftR = new double[samplesPerCycle]; for(int i = 0; i < samplesPerCycle; i++) { // don't even know why,... fftL[i] = 0; fftR[i] = 0; } fft = new DoubleFFT_1D(samplesPerCycle); ..... for(int i = 0; i < samplesPerCycle; i++) { audioIn.GetStereoSamples(temp); audioL[i]=temp[0]; audioR[i]=temp[1]; } fft.realForwardFull(audioL); //still stereo fft.realForwardFull(audioR); System.out.println("Check"); for(int i = 0; i < samplesPerCycle; i++) { //storing the magnitude in the fftL/R arrays fftL[i] = Math.sqrt(audioL[2*i]*audioL[2*i] + audioL[2*i+1]*audioL[2*i+1]); fftR[i] = Math.sqrt(audioR[2*i]*audioR[2*i] + audioR[2*i+1]*audioR[2*i+1]); } So the question is, if I want to know, what frequencys are in the sampled signal, how do I calculate them? (When I want to print the fftL / fftR arrays, I get some exponential formes at both ends of the array.) Thx :)

    Read the article

  • antlr: Best practice to integrate generated parser into the system

    - by green
    Here is the background, I am trying to create a DSL to allow customer write simple scripts to query into our mongodb based database. I choose antlr to implement the DSL. From my understanding (and pls let me know if it's not correct) there are 2 approaches to integrate antlr generated parser into the system: Embed code into the grammar file so that the generated parser could be used directly to make query to the database and return result in a certain format (e.g. json encoded) Keep the parser purely a parser, after feed the DSL file to it, and construct the query in another class by retrieving the AST from generated parser class So antlrers, which one do you think is the way I as an antlr newbie should go? Can you list the pros and cos of each approach, or you have other way to recommend?

    Read the article

  • Having Latest Tests Results info in the notified email with Hudson

    - by Roberto
    I have a project with a lot of tests failing, so it would be great for me to receive by email the number of failed tests compare from the latest build. What i need is just the info that appears in the project's page by the test results link: Latest Test Result (10 failures / -2) Is this possible? I've already tried the email-ext plugin, but it is not telling me that info (I can have the list of failing tests with output etc., but I really just need that info above). Any ideas?

    Read the article

  • how to use append function in file

    - by sadia
    I want to write in a file but in a way that it should not delete existing data in that file rather it should append that file. Can anybody please help by giving any example related to appending a file? Thank you

    Read the article

  • How to see "anti if" movement and its gaol?

    - by Vijay Shanker
    I have a developer for last 3 years, have been using if-else or if-else if statements a lot in my programing habit. And today, I found This link. One obvious sample i put here public void doSomthing(String target, String object){ //validate requests if(target != null && target.trim().length() < 1){ //invalid request; } //further logic } Now, I have seen this sort of check all over the places, libraries. So, I wanted to have a discussion about the worthiness of such a movement. Please let me know your views.

    Read the article

  • How to move positions within an array?

    - by Jade Mulholland
    A program that simply moves array elements. Two variables: userInputVariable and blankSpaceVariable. I have a 2D array named table. Defined as table[userInputVariable + 1][6] I am printing out this array in a table format, and the far left column is numbered by whatever number the user entered at the beginning of the program. I then ask the user where they would like to enter a blank space within the array. This blank space acts like a divider for all the other information in the array. For example, if the user enters 10 at the start for the userInputVariable, and then enters 5 for the blank space. Once printed, the numbers should go like this: 1, 2, 3, 4, --, 5, 6, 7, 8, 9, 10. My plan has been to create a for loop and try to move all the numbers in the array back a position starting from the blank space variable. What I currently have, but does not work: for (int i = blankSpaceVariable; i < table.length - 1; i++) { table[i] = table[i + 1]; } table[blankSpaceVariable] = "--"; With my current code, the numbers go like this: 1, 2, 3, 4, 6, 7, 8, 9, 10 Tried completing this a few different ways also, but the other info within my 2D array didn't move with the numbers. So I thought that this approach can hopefully move all the info within my 2D array down, and make way for a blank section. All help is greatly appreciated!

    Read the article

  • When i add a bitmap to an array list the last element is duplicated in previous indexes

    - by saxofone2
    I'm trying to implement a personal way of undo/redo in a finger paint-like app. I have in synthesis three objects: the Main class (named ScorePadActivity), the relative Main Layout (with buttons, menus, etc, as well as a View object where I create my drawings), and a third object named ArrayList where i'm writing the undo/redo code. The problem is, when I press the undo button nothing happens, but if I draw anything again "one-time" and press undo, the screen is updated. If I draw many times, to see any changes happen on screen I have to press the undo button the same number of times I have drawn. Seems like (as in title) when I add a bitmap to the array list the last element is duplicated in previous indexes, and for some strange reason, everytime I press the Undo Button, the system is ok for one time, but starts to duplicate until the next undo. The index increase is verified with a series of System.out.println inserted in code. Now when I draw something on screen, the array list is updated with the code inserted after the invocation of touchup(); method in motionEvent touch_up(); } this.arrayClass.incrementArray(mBitmap); mPath.rewind(); invalidate(); and in ArrayList activity; public void incrementArray(Bitmap mBitmap) { this._mBitmap=mBitmap; _size=undoArray.size(); undoArray.add(_size, _mBitmap); } (All Logs removed for clear reading) The undo button in ScorePadActivity calls the undo method in View activity: Button undobtn= (Button)findViewById(R.id.undo); undobtn.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { mView.undo(); } }); in View activity: public void undo() { this.mBitmap= arrayClass.undo(); mCanvas = new Canvas(mBitmap); mPath.rewind(); invalidate(); } that calls the relative undo method in ArrayList activity: public Bitmap undo() { // TODO Auto-generated method stub _size=undoArray.size(); if (_size>1) { undoArray.remove(_size-1); _size=undoArray.size(); _mBitmap = ((Bitmap) undoArray.get(_size-1)).copy(Bitmap.Config.ARGB_8888,true); } return _mBitmap; } return mBitmap and invalidate: Due to my bad English I have made a scheme to make the problem more clear: I have tried with HashMap, with a simple array, I have tried to change mPath.rewind(); with reset();, new Path(); etc but nothing. Why? Sorry for the complex answer, i want give you a great thanks in advance. Best regards

    Read the article

  • Getting instance of a class in ArrayList

    - by user1499974
    I have a small problem with ArrayList. You see, I wish to get an instance of RenderNewHUD in my renderer class, which has a list of registered renderers. I did not want to create a variable for this due to limitations and awkwardness. Here is my code. RenderNewHUD hud = renderer.renderList.get(RenderNewHUD()); How exactly can I go along getting the instance of RenderNewHUD without creating a new instance? If you need any more of my code, just ask. Sorry if this is a very dumb question - I have looked EVERYWHERE for an answer.

    Read the article

  • Entities equals() - hashcode() - toString(). How to correctly implement them?

    - by spike07
    I'm implementing equals() - hashcode() - toString() of my Entities using all the available fields in the bean. I'm getting some Lazy init Exception on the frontend when I try to compare the equality or when I print the obj state. That's because some list in the entity can be lazy initialized. I'm wondering what's the correct way to for implementing equals() and toString() on an Entity Obj

    Read the article

  • PropertyUtils performance

    - by mR_fr0g
    I have a problem where i need to walk through an object graph and pick out a particular property value. My original solution caches a linked list of property names that need to be applied in order to get from point A to point B in the object graph. I then use apache commons PropertyUtils to iterate through the linked list calling getProperty(Object bean, String name) until i have reached point B. My question is around how this will perform compared to perhaps cahing the Method objects for each step. What is propertyUtils doing under the bonnet? Is it doing a lot of reflection / heavy lifting?

    Read the article

  • Detecting mouse enter/exit events anywhere on JPanel

    - by Mano
    Hi, Basically there is a JPanel on which I want to know when the mouse enters the area of the JPanel and exits the area of the JPanel. So I added a mouse listener, but if there are components on the JPanel and the mouse goes over one of them it is detected as an exit on the JPanel, even though the component is on the JPanel. I was wondering whether anyone knows any way to solve this problem without doing something like adding listeners onto all components on the JPanel?

    Read the article

  • cant print the data of the uploaded blob

    - by Bunny Rabbit
    int start=0,flag=1; long size=blobInfo.getSize(),fetched=0,fetch; byte temp[] = null; while(fetched<size){ if(size-fetched>MAX_BLOB_FETCH_SIZE) fetch=MAX_BLOB_FETCH_SIZE; else fetch=size-fetched; temp=blobstoreService.fetchData(blobKey,fetched,fetch ); fetched+=fetch; out.println(temp); } i tried to print the data of the uploaded text file using the above code but it doesn't seem to be working .

    Read the article

  • Resources access problem from JAR

    - by aeter
    I have the following directory structure of a project: Folder "project" in Eclipse: --folder "src" --folder "resources" ----trayicon2.png --folder "db" ----test.db --folder "bin" I'm accessing the image with: Image image = Toolkit.getDefaultToolkit().getImage("resources/trayicon2.png"); and from Eclipse that is not a problem. Then I generate an "executable jar file", and add the dirs, making a directory structure of: Folder "project" --folder "db" ----test.db --folder "resources" ----trayicon2.png --project.jar And now the image is no more accessible. Also, the database is no more accessible; while in Eclipse I used to access it with: Connection conn = DriverManager.getConnection("jdbc:sqlite:db/test.db"); How can I access the resources (images and db) after generating the jar file "project.jar"?

    Read the article

  • Static method,new thread performance question

    - by ylazez
    Hey guys i just have two questions about two methods used in many controllers/servlets in my app: 1-what is the difference between calling a static method in a util class or a non static method (like methods dealing with dates i.e getting current time,converting between timezones), which is better ? 2-what is the difference between calling a method(contain too many logic like sending emails) in the controller directly or running this method in a different thread ?

    Read the article

  • why we can't initialize a servlet using constructor itself?

    - by Reddy
    Why do we have to override init() method in Servlets while we can do the initialization in the constructor and have web container call the constructor passing ServletConfig reference to servlet while calling constructor? Ofcourse container has to use reflection for this but container has to use reflection anyway to call a simple no-arg constructor

    Read the article

  • Redirect from docroot to an external url in glassfish

    - by tim_wonil
    I've googled around and only found solution where they suggest putting an apache httpd in front of glassfish. Sure, that works. But what if I do not wish to/cannot put any thing in front of glassfish? Without using the index.jsp in the docroot of the domain to have something like: <% String redirectURL = "http://stackoverflow.com/"; response.sendRedirect(redirectURL); %> Can I make browser to be redirected when I point it to: http://my.glassfish.domain/ ?

    Read the article

  • Configuring servlet for using spring

    - by dominolog
    Hello How to configure my web application in Eclipse (based on Servlets and deployed to Tomcat) to use Spring framework. I need only IoC container (Beans only and ApplicationContext), not Spring MVC. How to configure web.xml for this? Regards

    Read the article

  • JPA and compatibility with persistance providers and databases vendors

    - by Kartoch
    JPA promises to be vendor neutral for persistence and database. But I already know than some persistence frameworks like hibernate are not perfect (character encoding, null comparison) and you need to adapt your schema for each database. Because there is two layers (the persistence framework and database), I would imagine they're some work to use some JPA codes... Does anyone has some experiences with multiple support and if yes, what are the tricks and recommendations to avoid such incompatibilities ?

    Read the article

  • best way to avoid sql injection

    - by aauser
    I got similar domain model 1) User. Every user got many cities. @OneToMany(targetEntity=adv.domain.City.class...) 2) City. Every city got many districts @OneToMany(targetEntity=adv.domain.Distinct.class) 3) Distintc My goal is to delete distinct when user press delete button in browser. After that controller get id of distinct and pass it to bussiness layer. Where method DistinctService.deleteDistinct(Long distinctId) should delegate deliting to DAO layer. So my question is where to put security restrictions and what is the best way to accomplish it. I want to be sure that i delete distinct of the real user, that is the real owner of city, and city is the real owner of distinct. So nobody exept the owner can't delete ditinct using simple url like localhost/deleteDistinct/5. I can get user from httpSession in my controller and pass it to bussiness layer. After that i can get all cities of this user and itrate over them to be sure, that of the citie.id == distinct.city_id and then delete distinct. But it's rather ridiculous in my opinion. Also i can write sql query like this ... delete from t_distinct where t_distinct.city_id in (select t_city.id from t_city left join t_user on t_user.id = t_city.owner_id where t_user.id = ?) and t_distinct.id = ? So what is the best practice to add restrictions like this. I'm using Hibernate, Spring, Spring MVC by the way.. Thank you

    Read the article

  • Any way to make a generic List where I can add a type AND a subtype?

    - by user383178
    I understand why I cannot do the following: private class Parent { }; private class Child extends Parent { }; private class GrandChild extends Child { }; public void wontCompile(List<? extends Parent> genericList, Child itemToAdd) { genericList.add(itemToAdd); } My question is there ANY practical way to have a typesafe List where you can call add(E) where E is known to be only a Parent or a Child? I vaguely remember some use of the "|" operator as used for wildcard bounds, but I cannot find it in the spec... Thanks!

    Read the article

  • Is there a simpliest way of doing this?

    - by Tom Brito
    Is there a simpler way of implement this? Or a implemented method in JDK or other lib? /** * Convert a byte array to 2-byte-size hexadecimal String. */ public static String to2DigitsHex(byte[] bytes) { String hexData = ""; for (int i = 0; i < bytes.length; i++) { int intV = bytes[i] & 0xFF; // positive int String hexV = Integer.toHexString(intV); if (hexV.length() < 2) { hexV = "0" + hexV; } hexData += hexV; } return hexData; } public static void main(String[] args) { System.out.println(to2DigitsHex(new byte[] {8, 10, 12})); } the output is: "08 0C 0A" (without the spaces)

    Read the article

  • How do I get the name of the test method that was run in a testng tear down method?

    - by Zachary Spencer
    Basically I have a tear down method that I want to log to the console which test was just run. How would I go about getting that string? I can get the class name, but I want the actual method that was just executed. Class testSomething() { @AfterMethod public void tearDown() { system.out.println('The test that just ran was....' + getTestThatJustRanMethodName()'); } @Test public void testCase() { assertTrue(1==1); } } should output to the screen: "The test that just ran was.... testCase" However I don't know the magic that getTestThatJustRanMethodName should actually be.

    Read the article

  • Hibernate Native Query problem with named parameters

    - by dime
    I have a problem with Hibernate Native Query. I have one SELECT that selects array slice (PostgreSQL database). The problem is that hibernate recognizes the following part: ":300" from "SELECT my_array[1:300]..." as named parameter and I get the following exception: Not all named parameters have been set. I tried to escape the colon (:) with '\:' , '::' but with no success. The Hibernate version is 3.2

    Read the article

< Previous Page | 912 913 914 915 916 917 918 919 920 921 922 923  | Next Page >