Re: Want to know how to inluce octave fft lib in my Qt program

[c.]

Hi,

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>>> On 7 Oct 2013, at 08:40, Prasanth N P <address@hidden> wrote:
>>> 
>>> > Hi,
>>> > Hi,
>>> > I want to know how to use the fft function in octave in my qt program. 
>>> > Currenly I have a set of samples and want to do the fft of these with 
>>> > octave fft function. How can I do this?
>>> -- 
>>> Thanks & Regards,
>>> Prasanth NP
>> 
>> On Mon, Oct 7, 2013 at 6:34 PM, c. <address@hidden> wrote:
>> 
>> Octave's fft function is just a wrapper for the fftw library [1],
>> so if you have a C/C++ program it's probably easier for you to
>> use fftw directly.
>> 
>> HTH,
>> c.
>> 
>> [1] http://www.fftw.org/
>> 
>> 
> On 9 Oct 2013, at 10:23, Prasanth N P <address@hidden> wrote:

> 
> But i have to use the ellip filter too in this  case, If I use the seperate 
> lib of fftw, I have to find the seperate filter function also. So it is 
> better to use the octave lib. Here is my problem
> 
> I have to use those computation in my qt program. But currently I made this 
> through system call
> 
> myprogram.cpp
> 
>        system("octave -qf shellLof.m");
> 
> 
> shellLof.m
> 
>         load 'Data'
>         setenv ("GNUTERM", "x11")
>         t=1/SF;
>         l=2048;
>         v=fft(Data,l)/l;
>         V = v(1:l/2);
> 
>         save fftdata V;
> 
> 
> Finally 'fftdata' file loaded in the myprogram.cpp. Can I use the fft 
> function of octave without calling this shell program?
> -- 
> Thanks & Regards,
> Prasanth NP

Yes, 

you can use the function "feval" to invoke the Octave interpreter from within a 
C++ application,
there is an exemple of how to do this inside the Octave source tree, look for 
the file named

  examples/embedded.cc

HTH,
c.