similar to: Real FFT

Displaying 20 results from an estimated 300 matches similar to: "Real FFT"

2012 Apr 23
2
automating a script to read a file
Hi, The following script (which I did not develop) is used to calculate and plot a skewed normal curve. The script currently requires the user to input six parameters, rather than reading these directly from a file. I've been spinning wheels here, trying to figure out how to modify the script to automate it. I have four data sets, each in excess of 300 records that I need to process. My
2004 Sep 15
6
Bessel function
Dear all Currently, I'm implementing the generalized hyperbolic distribution into Splus. Unfortunately the Bessel function is not implemented in Splus. In R the Bessel function does exist but it is an internal function and I'm not able to look at the code. Is there any possibility to see the code of the Bessel function in R or does anybody has an implementation of the Bessel function in
2007 Jun 27
1
User mapping via pam
Hi, I'm trying to change the PAM_USER within a pam module, and observed that dovecot 0.99 does not support this. I then looked at 1.x and found: src/auth/passdb-pam.c:232: /* FIXME: this doesn't actually work since we're in the child process.. */ status = pam_get_item(pamh, PAM_USER, (linux_const void **)&item); if (status !=
2007 Sep 07
0
[LLVMdev] Compile Linux Kernel with LLVM gcc frontend
On Fri, 31 Aug 2007, Patrick Flannery wrote: > I can say that it does not for me,running x86_64, I have been generating > errors for submission by testing on a number of gnu utilities starting > with binutils. If you run into problems, please file bugs. -Chris > On Aug 31, 2007, at 6:11 PM, "Haifeng He" <hehaifeng2nd at gmail.com> wrote: > > Hi, > > I
2008 Jul 30
1
Setting fixed size for segement plot using stars() (axes size vs print size)
I have been making some segment plots with five variables. They work great, especially when I used a different scale function, which scaled them by area of the circle rather than radius scale <- function(x, Mr = 1 , Mx = 100) { ((x/Mx)^.5)*Mr} Where x is the the value, Mr is the Maximum radius, and Mx is the maximum data value. You could change the exponent .5 to .57 if you wanted Flannery
2007 Jun 08
3
CentOS and Wordpress
Hi All, I am currently am responsible for maintaining a website built on Apache 2, running on some CentOS 4 (64 bit version) boxes. Thus far, the website has comprised a few HTML pages, and some dynamic pages generated by perl scripts. The CentOS install is pretty vanilla -- the only departure I've made from the default server install is to install awstats from the rpmforge repositories.
2005 Mar 14
4
The corresponding Fortran77 codes for R function pt()
Hi, I'm trying to find the corresponding Fortran77 subroutines for R function pt(). I tried some Fortran77 subroutines to compute the t distribution function. But none of them are as good as R function pt(). Does anyone can give me some information about it? Thank you very much! Tianyue
2014 Jan 11
1
Fortran BLAS giving bad results
Hello r-devel, When compiling Fortran code containing BLAS functions and calling it using dyn.load, I am getting incorrect results. A small example with which I can reproduce the problem is below. I am running on OSX Mavericks (upgraded R, Xcode, etc per instructions on this list), but I do not think it is related since the check on my "blupsurv" package on r-forge seems to be showing
2014 Dec 25
0
[RFC][FFT][Fixed-Point][NEON] NEON-Optimize Fixed-Point FFT?
> I am working on DSP module of Ne10. I see there are fixed-point and > floating-point FFT inside Opus. Is fixed-point FFT only a fall back for CPU > without VFP? On ARMv7-A and ARMv8-A, benchmark result shows that fixed-point > (int32) and floating-point (float32) FFT have similar performance. I guess > fixed-point version is not often used on these platforms. Is it worth the >
2014 Dec 25
0
[RFC][FFT][Fixed-Point][NEON] NEON-Optimize Fixed-Point FFT?
There is definitely some use for a Neon fixed-point FFT. How much exactly I'm not sure. Fixed-point is a bit more than just a fall-back for CPUs with no FPU. There are CPUs for which fixed-point is still faster. It depends on the exact model but also on what you run. For example, even on x86 I believe that SILK encoding is slightly faster in fixed-point, even though CELT is faster in float.
2014 Dec 26
0
[RFC][FFT][Fixed-Point][NEON] NEON-Optimize Fixed-Point FFT?
Thanks Timothy and Jean-Marc, I will start NEON optimizing fixed-point FFT. Is it int32 good enough? Benchmark data shows that FFT using int16 is much faster than FFT using int32. > -----Original Message----- > From: Timothy B. Terriberry [mailto:tterribe at xiph.org] > Sent: Friday, December 26, 2014 6:52 AM > To: Phil Wang; opus at xiph.org > Cc: Zhongwei Yao; Yang Zhang; Zhou
1997 Dec 11
1
R-alpha: fft does not act as described in help(fft)
Hello! thank you for your efforts creating R! While preparing the next lessons I found that I had to multiply with 1/length(x) by hand if I want to get the inverse Fouriertransform. The help states it will do it by itself. Version R-0.60.1, Linux Seems to be pretty easy to correct either the fft or :-) the help(fft)! Cu Detlef Detlef Steuer Universitaet Dortmund ///////
2014 Nov 25
1
[Profiling][FFT][AArch64] FFT Profiling data on AArch64
Hi everyone, I have profiled Opus on AArch64. I just run opus_demo with some pcm files. Following is time proportion of FFT with different bitrate. Bitrate | Time cost by FFT/iFFT 24kb/s | 15% 48kb/s | 15% 96kb/s | 13% Any comment? I want some data close to real application, any suggestion? Thanks, Phil Wang -------------- next part -------------- An HTML attachment was scrubbed... URL:
2014 Dec 25
2
[RFC][FFT][Fixed-Point][NEON] NEON-Optimize Fixed-Point FFT?
Jean-Marc Valin wrote: > There is definitely some use for a Neon fixed-point FFT. How much > exactly I'm not sure. Fixed-point is a bit more than just a fall-back Well, we use fixed-point mode by default in Firefox for both Firefox OS and Fennec (Firefox on Android). The reason is that, although there is some NEON-class hardware where float does finally appear to be a little bit
2014 Dec 24
6
[RFC][FFT][Fixed-Point][NEON] NEON-Optimize Fixed-Point FFT?
Hi, I am working on DSP module of Ne10. I see there are fixed-point and floating-point FFT inside Opus. Is fixed-point FFT only a fall back for CPU without VFP? On ARMv7-A and ARMv8-A, benchmark result shows that fixed-point (int32) and floating-point (float32) FFT have similar performance. I guess fixed-point version is not often used on these platforms. Is it worth the effort to NEON-optimize
2012 Dec 07
0
fft and wavenumber
Hi I need to compute the fft of an image A with dimension (Nx,Ny) and are not sure on how to compute the wavenumber. I have done like that but i am not sure i am computing the wavenumber in the correct way..can someone help? sara image.plot(x,y,A) dx = diff(x)[1] dy = diff(y)[1]      ## This is equivalent to what the matlab fftshift function does fzs = fft(A) Fzs  = fftshift2D(fzs)/(Nx*Ny);
2003 Jan 09
1
fft(x, inv=TRUE)
I started out with a real vector b and then obtained its Fourier transform thus B<-fft(b) When I did F<-fft(B, inv=TRUE) I expected that F would be the inverse FT of B but it still has imaginary components. Should the inverse FT not be purely real? Am I missing something? Thanks, Peter.
2010 May 30
1
Calling fft from C
Hi I have made a R function 'convolve2' for convolution of two real valued vectors based on Rs 'convolve' with option type="open" - see below. (exp.length and irf.length are variables set in another part of the program) I wish to implement the function convolve2 in C and use it in a function used from R with .Call - e.g. I need to call fft in C. All I can find in the
2005 Jul 26
0
a question about fft ( fast fourier transform)
Dear listers In R, if I have a sequence x(t), t=1,...N, fft(x) is actually giving us sum(x(t)exp(-i*omega*t)) at fourier frequency omega= 2*pi*i/N, i=0,1,...(N-1). The question is if I want to calculate sum(x(t)exp(-i*2*omega*t)), how can I do it? thanks a lot! ------------------------------- liyun (Lauren) Ma Dept of Statistics North Carolina State University
2009 Nov 10
0
how to compute Autocorrelation function use fft
Dear all£¬ Could you tell me how to compute Autocorrelation function use fft? Thanks! [[alternative HTML version deleted]]