Search DaniWeb - fft

Re: FFT implementation 16 Years Ago by JamesCherrill FFT method gets pixel values in variable pix (via grabPix), but then tries to use the parameter pixels, which doesn't seem to get populated anywhere. If you use CODE=Java /CODE tags we'll have line numbers to make thing seasier. FFT Implementation in ImageJ not working 10 Years Ago by sel15 …0; i<widthSize; i++) { FHTreal(i, widthSize, fft, real); FHTimag(i, widthSize, fft, imag); } finalArray = four1(fdata, fdata.length/4,1…; System.out.println(finalArray.length); } And this is the algorithm (FFT): public float[] four1(float data[], int nn, int isign) {… Re: FFT implementation 16 Years Ago by jooa …CODE] public static void main(String[] args) { FFT fft = new FFT(pix, width, height); fft.transform(); } }[/CODE] [CODE]package FFTMain; …); transform(); } } /** * Method to recursively apply the 1D FFT to a ComplexNumber array. * * @param x A ComplexNumber array… Re: FFT implementation 16 Years Ago by jooa …h); transform(); } } /** * Method to recursively apply the 1D FFT to a ComplexNumber array. * * @param x A ComplexNumber array …* @return A ComplexNumber array containing the result of the 1D FFT. */ static ComplexNumber[] recursiveFFT(ComplexNumber[] x) { ComplexNumber z1, … FFT implementation 16 Years Ago by jooa …which extracts a pixel array from an image, the class FFT implements the transform. My problem is I don't think… the methods in the FFT class are being applies because the output I get … * of complex numbers. ie The result of applying the 2D FFT to an image. * */ public class TwoDArray{ /** * The actual width … Re: FFT implementation 16 Years Ago by JamesCherrill That's a lot of code to scan, but I can't find anywhere where you actually call anything to do an FFT. And maybe I'm being dumb, but I can't find any code to do an FFT anyway. Can you point me in the right direction? Re: FFT implementation 16 Years Ago by JamesCherrill 1. You seem to call transform(); twice - once in new FFT(...) and again immediately after in main(...). 2. How do you know it's not working - I don't see anything that would output the results in a format that you could check? FFT Algorithm Variation 15 Years Ago by Peter_APIIT Hello to all, as you all know FFT algorithm has many variation in terms from its pruposes. My requirement of FFT is integer multiplication and polynomial evaluation. I looking for good reference about the topic. If you have any, please post it here. Thanks. FFT Cooley Tukey 12 Years Ago by phorce …'m trying to write the Cooley Turkey algorithm for an FFT. Now, The algorithm works well, but, only for 2 numbers… - Nothing else. For example, I have used an online FFT calculated, entered the same data and got the same results… Re: FFT Algorithm Variation 15 Years Ago by Peter_APIIT …] What you mean by 2d form ? Is GSL using colley_turkey FFT or other variation ? What is radix and non-radix2 ? Thanks… Re: FFT Algorithm Variation 15 Years Ago by StuXYZ Yes the GSL algorithms provide a colley-tukey FFT but as you know, this is requires the data set … Re: FFT Audio Analysis 15 Years Ago by Gribouillis I can give you a hint [code=python] >>> from scipy.fftpack import fft [/code] and [url=http://www.scipy.org/SciPyPackages/Fftpack]a link[/url]. Now, all you have to do is to obtain an array of sampled data, call the function and get another array, the fft of the first. Next step: understand the meaning of the output. FFT Audio Analysis 15 Years Ago by computerfreak97 Can anyone give me an example on how to use fft to see weather there is a certain frequency above a certain amplitude in the microphones current sample(s). Re: FFT Audio Analysis 15 Years Ago by computerfreak97 Alright, now what does the output of the fft mean? Re: FFT Audio Analysis 15 Years Ago by Gribouillis … a plotted result of both the sample and it's fft, it would be great. Python FFT finding frequencies-Numpy 14 Years Ago by Masood_786 …**8 # ADJUST THIS TO CHANGE SPEED/SIZE OF FFT sampleRate=48100 #sampleRate=64000 p = pyaudio.PyAudio() …-degree:i+degree])/(degree*2)) #ly.append(fft[i]-(ffty[i-degree]+ffty[i+degree])/2…float(sampleRate),"SEC" ffty=scipy.fftpack.fft(data) fftx=scipy.fftpack.rfftfreq(bufferSize*2,… Re: Python FFT finding frequencies-Numpy 14 Years Ago by Masood_786 …import math #ADJUST THIS TO CHANGE SPEED/SIZE OF FFT bufferSize=2**11 #bufferSize=2**8 # ADJUST …THIS TO CHANGE SPEED/SIZE OF FFT sampleRate=48100 #sampleRate=64000 p = pyaudio.PyAudio() chunks=[]…)/float(sampleRate),"SEC" ffty=scipy.fftpack.fft(data) fftx=scipy.fftpack.rfftfreq(bufferSize*2, 1… Re: Input wav file Output Spectrogram using FFT algorithm 15 Years Ago by gonzi.p12 …class today 2) now u can apply the FFT on your raw data. and u will get…to actually play the sound and display the FFT diagram at that moment. things to be aware…lot of processing power so start with an FFT on about 3-5 millisecond of your …from the wave file....... Secondly I can perform FFT on numerical values. These numerical Values will be… Perform Hamming window and FFT with Java 14 Years Ago by cielle …soundSample[1000] with window length 100. Then proceed with FFT. And i found that java does have the package… for Hamming window and FFT. As below, [url]http://code.compartmental.net/minim/…javadoc/ddf/minim/analysis/FFT.html[/url] [url]http://marf.sourceforge.net/api/marf… Using FFT to compare two audio files and then realtime comparison 13 Years Ago by arshad115 … to compare it to the input stream. I have applied FFT using this API as it is compatible with Android: http… know much about this api either but, I think the FFT data is stored in FrequencyTimeDomainRepresentation object. I searched on the… compare the data. Please tell me how to compare the FFT data and how do I match the saved file data… Convert FFT python to C# 4 Years Ago by shiv.manoj23 … Python example - Fourier transform using numpy.fft method import numpy as np import matplotlib.pyplot…('Amplitude') # Frequency domain representation fourierTransform = np.fft.fft(amplitude)/len(amplitude) # Normalize amplitude fourierTransform = fourierTransform… Re: Input wav file Output Spectrogram using FFT algorithm 15 Years Ago by SwiftSilver … my WavReader class today 2) now u can apply the FFT on your raw data. and u will get a three… your program to actually play the sound and display the FFT diagram at that moment. things to be aware of is… a lot of processing power so start with an FFT on about 3-5 millisecond of your sound data. thats … Re: Help understanding FFT and/or DSP 14 Years Ago by Software guy …. But I am afraid it cannot help you in programming. FFT is further derivation of Fourier series. Because the problem with… is that you cannot use it for aperiodic signals. But FFT can be used for aperiodic signals, because we assume that… this assumption. Whatever I wrote might not make sense, but FFT can give you the DFT of each sample in audio… Re: Convert FFT python to C# 4 Years Ago by rproffitt … care here. My background does include DSP work which had FFT in various languages but your lack of care has me… program's goals are untold. I see more than a FFT here with what looks to be graphical output. That is… Passing FFT data to an Editbox in an MFC App 16 Years Ago by Sarlacc I have been trying to learn about FFT programs and have been using one of the codeprojects example … is how to go about taking the data from the fft algorithm that is used here and display that information in… Periodic noise remove from image with Matlab fft 14 Years Ago by butkovm … is far from to be clean. I have attached fft of input image, fft of output image (after i have removed noises… Re: Perform Hamming window and FFT with Java 14 Years Ago by Akill10 crossposted here: [url]http://www.java-forums.org/advanced-java/36607-perform-hamming-window-fft-java.html[/url] You should link to all your crossposts, that way, if you find the answer in one of them, it may allow somebody searching for the same answer to find it easier. Re: Perform Hamming window and FFT with Java 14 Years Ago by cielle …://www.java-forums.org/advanced-java/36607-perform-hamming-window-fft-java.html[/url] You should link to all your crossposts… Re: Input wav file Output Spectrogram using FFT algorithm 15 Years Ago by gonzi.p12 … the data from the wave file....... Secondly I can perform FFT on numerical values. These numerical Values will be present in… the data from the wave file....... Secondly I can perform FFT on numerical values. These numerical Values will be present in… Input wav file Output Spectrogram using FFT algorithm 15 Years Ago by gonzi.p12 … the wav file in C and sample it and apply FFT algorithm.. And output should be an spectrogram. can any body…