fftw

问题 I'm trying to link third party libraries like fftw3 and sndfile to my iPhone project in Xcode3.2. I got it working in a regular Mac project by setting the "Header Search Path" to "/usr/local/include" and the "Other Linker Flags" to "-lfftw3 -lsndfile" under the project build configuration. However, it gave me "library not found for -lfftw3" with exit code 1 error message when I tried to build it in the iPhone project using the same settings. Does apple not allow this on the iPhone? Is there a

问题 I'm trying to use FFTW in my Android application. I have followed this tutorial and was able to buid fftw with floating point precision using this build.sh, on OSX: INSTALL_DIR="`pwd`/jni/fftw3" SRC_DIR="`pwd`/../fftw-3.3.3" NDK_ROOT="/Users/awesomeUserName/Desktop/android-ndk-r9" cd $SRC_DIR export PATH="$NDK_ROOT/toolchains/arm-linux-androideabi-4.8/prebuilt/darwin-x86_64/bin/:$PATH" export SYS_ROOT="$NDK_ROOT/platforms/android-14/arch-arm/" export CC="arm-linux-androideabi-gcc --sysroot=

问题 I used to use fftw_plan_dft for multi-dimensional Fourier transformation. fftw_plan fftw_plan_dft(int rank, const int *n, fftw_complex *in, fftw_complex *out, int sign, unsigned flags); Now I want to pass 64 bit integer to fftw, it looks like I need to use fftw guru interface. fftw_plan fftw_plan_guru64_dft( int rank, const fftw_iodim64 *dims, int howmany_rank, const fftw_iodim64 *howmany_dims, fftw_complex *in, fftw_complex *out, int sign, unsigned flags); But I do not understand what is

问题 I wrote a simple test program in order to implement the FFTW with MPI in a 2d domain (with Fortran). The domain is 'Ny x Nx' wide and partitioned in the second ('x') index. After proper (I believe?) declaration and allocation of variables and plans, I call the fftw_mpi r2c_2d function and next I transform back its output with the fftw_mpi c2r_2d, in order to check if I get the original input. The r2c_2d part seems to work fine. However, I don't get the original input after transforming back

问题 I am trying to do a 3D FFT with the FFTW library, but I have some difficulties with the inverse transformation. At first I do the foreword transformation via: fftwf_plan_dft_3d(_dimensions[0], _dimensions[1], _dimensions[2], (fftwf_complex*)_inputBuffer, (fftwf_complex*)_outputBuffer, FFTW_FORWARD, FFTW_ESTIMATE); Although my data is real data I am using the complex to complex transformation, as want to replace it later by an opencl fft which only supports complex to complex transformations.

问题 I have installed fftw C library succefully on my linux system. Here is more info about fftw c => http://www.fftw.org/ I have a sample C code which can call fftw C functions successfully. Below is a C ccode and command to run the C code: Code: #include <stdio.h> #include <stdlib.h> #include <stdint.h> #include <math.h> #include <fftw3.h> int main(void) { double FFT_in[] = {0.1, 0.6, 0.1, 0.4, 0.5, 0, 0.8, 0.7, 0.8, 0.6, 0.1,0}; double *IFFT_out; int i,size = 12; fftw_complex *middle; fftw_plan

问题 I am currently writing a genre classification application as my final year project in Computer Engineering. I initially wrote the feature extraction code (implementing FFTW) in C and now I need to implement it on Android via the NDK. This is my first NDK project so I'm still getting the hang of things but I have compiled the FFTW3 library for Android according to this guide. I didn't do the very last step because I didn't think it was right for what I need. My question is how do I, after the

问题 I am trying to perform several FFT's in parallel. I am using FFTW and OpenMP. Each FFT is different, so I'm not relying on FFTW's build-in multithreading (which I know uses OpenMP). int m; // assume: // int numberOfColumns = 100; // int numberOfRows = 100; #pragma omp parallel for default(none) private(m) shared(numberOfColumns, numberOfRows)// num_threads(4) for(m = 0; m < 36; m++){ // create pointers double *inputTest; fftw_complex *outputTest; fftw_plan testPlan; // preallocate vectors for

问题 I am compiling a test program to test the fftw3 (ver3.3.4). Since it is not installed with root previlidge the command I used is: gcc -lm -L/home/my_name/opt/fftw-3.3.4/lib/ -I/home/my_name/opt/fftw-3.3.4/include/ fftwtest.c where the library is installed in /home/my_name/opt/fftw-3.3.4/ My code is the 1st tutorial on fftw3's website: #include <stdio.h> #include <fftw3.h> int main(){ int n = 10; fftw_complex *in, *out; fftw_plan p; in = (fftw_complex*) fftw_malloc(n*sizeof(fftw_complex)); out

问题 For a project I need to be able to generate a spectrogram from a .WAV file. I've read the following should be done: Get N (transform size) samples Apply a window function Do a Fast Fourier Transform using the samples Normalise the output Generate spectrogram On the image below you see two spectrograms of a 10000 Hz sine wave both using the hanning window function. On the left you see a spectrogram generated by audacity and on the right my version. As you can see my version has a lot more