Well guys, it took a while because of the serious limitations of ARexx for a stock AMIGA A1200 but here is a working FFT for it. ARexx has no ARRAY facility but there is a workaround. ;o)
Boy oh boy, ARexx's arithmetic is so convoluted and floating point precision is not the best.
This was a challenge. I could have generated SIN, COS and SQRT in pure ARexx but decided to use an external ARexx math(s) library instead...
It would be just as easy to create SIN, COS and SQRT in ksh too eliminating awk entirely but awk just made it easier...
Just for the record the AMIGA shell/terminal has a large subset of xterm's escape codes.
An exercise in futility? Maybe but serious fun nevertheless...
This is through FS-UAE AMIGA emulation and my real A1200 setup for easy transfer from this Macbook Pro.
ARexx code:
Hello All,
Below is a simple script i worte to find the 208th char in a file. If the char = "C" then I re-direct the line to a file called change.txt. If it is not "C" then I re-direct it to a file called delete.txt.
My problem is I have a file 0f 500K lines. this script is very slow. I am... (4 Replies)
Any means of running ksh93 in a ksh88-mode?
Might sound odd, but I want/need to restrict U/Win-developed scripts to correspond to the ksh88 version on my Solaris environment(s). Thanks. (2 Replies)
I have a text file that contains 4 million lines, each line contains 2 fields(colon as field separator). as shown:
123:444,555,666,777,888,345
233:5444,555,666,777,888,345
623:454,585,664,773,888,345
......
Here I have to split the second field(can be up to 40,000 fields) by comma into an... (14 Replies)
Hi,
I have a script that, basically, has two input files of this type:
file1
key1=value1_1_1
key2=value1_2_1
key4=value1_4_1
...
file2
key2=value2_2_1
key2=value2_2_2
key3=value2_3_1
key4=value2_4_1
...
My files are 10k lines big each (approx).
The keys are strings that don't... (7 Replies)
Hi,
I have a large number of input files with two columns of numbers.
For example:
83 1453
99 3255
99 8482
99 7372
83 175
I only wish to retain lines where the numbers fullfil two requirements. E.g:
=83
1000<=<=2000
To do this I use the following... (10 Replies)
Hi Experts,
I have several shell scripts that have been developed on a Linux box for korn ksh93.
If we want to run this software on an AIX 6.1 box that runs ksh88 by default can we just change the she-bang line to reference /bin/ksh93 which ships with AIX as its "enhanced shell" to ensure... (6 Replies)
I don't know if anyone is interested but I have been meddling with FFT for the AMIGA.
(Sadly we AMIGAns don't have these luxuries through any scripting language.
Below is a Python snippet that uses the builtin 'cmath' module to work with the lowly
Python 2.0.1 for the AMIGA. It is part of a... (0 Replies)
Hi everyone !
Im trying to know from wich version of AIX KSH93 is available ?
Internet tell me 6.x and 7.x AIX are available, bue what about 5.x ?
Is KSH93 available on AIX 5.x ?
Is it the same way to manipulate variables as KSH93 on 7.x ?
Thanks for your support and have a nice day ! (2 Replies)
Hi guys...
This is code that was originally designed to work on an upgraded AMIGA A1200 using Python 2.0.x.
Unfortunately it broke inside much later versions, NOT because of the print statement/function but other minor subtleties. So this is the final result tested on various machines including... (0 Replies)
Discussion started by: wisecracker
0 Replies
LEARN ABOUT DEBIAN
pdl::fftw
FFTW(3pm) User Contributed Perl Documentation FFTW(3pm)NAME
PDL::FFTW - PDL interface to the Fastest Fourier Transform in the West v2.x
DESCRIPTION
This is a means to interface PDL with the FFTW library. It's similar to the standard FFT routine but it's usually faster and has support
for real transforms. It works well for the types of PDLs for which was the library was compiled (otherwise it must do conversions).
SYNOPSIS
use PDL::FFTW
load_wisdom("file_name");
out_cplx_pdl = fftw(in_cplx_pdl);
out_cplx_pdl = ifftw(in_cplx_pdl);
out_cplx_pdl = rfftw(in_real_pdl);
out_real_pdl = irfftw(in_cplx_pdl);
cplx_pdl = nfftw(cplx_pdl);
cplx_pdl = infftw(cplx_pdl);
cplx_pdl = Cmul(a_cplx_pdl, b_cplx_pdl);
cplx_pdl = Cconj(a_cplx_pdl);
real_pdl = Cmod(a_cplx_pdl);
real_pdl = Cmod2(a_cplx_pdl);
FFTW documentation
Please refer to the FFTW documentation for a better understanding of these functions.
Note that complex numbers are represented as piddles with leading dimension size 2 (real/imaginary pairs).
FUNCTIONS
load_wisdom
Loads the wisdom from a file for better FFTW performance.
The wisdom is automatically saved when the program ends. It will be automagically called when the variable $PDL::FFT::wisdom is set to a
file name. For example, the following is a useful idiom to have in your .perldlrc file:
$PDL::FFT::wisdom = "$ENV{HOME}/.fftwisdom"; # save fftw wisdom in this file
Explicit usage:
load_wisdom($fname);
fftw
calculate the complex FFT of a real piddle (complex input, complex output)
$pdl_cplx = fftw $pdl_cplx;
ifftw
Complex inverse FFT (complex input, complex output).
$pdl_cplx = ifftw $pdl_cplx;
nfftw
Complex inplace FFT (complex input, complex output).
$pdl_cplx = nfftw $pdl_cplx;
infftw
Complex inplace inverse FFT (complex input, complex output).
$pdl_cplx = infftw $pdl_cplx;
rfftw
Real FFT. For an input piddle of dimensions [n1,n2,...] the output is [2,(n1/2)+1,n2,...] (real input, complex output).
$pdl_cplx = fftw $pdl_real;
irfftw
Real inverse FFT. Have a look at rfftw to understand the format. USE ONLY an even n1! (complex input, real output)
$pdl_real = ifftw $pdl_cplx;
nrfftw
Real inplace FFT. If you want a transformation on a piddle with dimensions [n1,n2,....] you MUST pass in a piddle with dimensions
[2*(n1/2+1),n2,...] (real input, complex output).
Use with care due to dimension restrictions mentioned below. For details check the html docs that come with the fftw library.
$pdl_cplx = nrfftw $pdl_real;
inrfftw
Real inplace inverse FFT. Have a look at nrfftw to understand the format. USE ONLY an even first dimension size! (complex input, real
output)
$pdl_real = infftw $pdl_cplx;
rfftwconv
ND convolution using real ffts from the FFTW library
$conv = rfftwconv $im, kernctr $im, $k; # kernctr is from PDL::FFT
fftwconv
ND convolution using complex ffts from the FFTW library
Assumes real input!
$conv = fftwconv $im, kernctr $im, $k; # kernctr is from PDL::FFT
Cmul
Signature: (a(n); b(n); [o]c(n))
Cmul
Complex multiplication
$out_pdl_cplx = Cmul($a_pdl_cplx,$b_pdl_cplx);
Cmul does not process bad values. It will set the bad-value flag of all output piddles if the flag is set for any of the input piddles.
Cscale
Signature: (a(n); b(); [o]c(n))
Cscale
Complex by real multiplation.
$out_pdl_cplx = Cscale($a_pdl_cplx,$b_pdl_real);
Cscale does not process bad values. It will set the bad-value flag of all output piddles if the flag is set for any of the input piddles.
Cdiv
Signature: (a(n); b(n); [o]c(n))
Cdiv
Complex division.
$out_pdl_cplx = Cdiv($a_pdl_cplx,$b_pdl_cplx);
Cdiv does not process bad values. It will set the bad-value flag of all output piddles if the flag is set for any of the input piddles.
Cbmul
Signature: (a(n); b(n))
Cbmul
Complex inplace multiplication.
Cbmul($a_pdl_cplx,$b_pdl_cplx);
Cbmul does not process bad values. It will set the bad-value flag of all output piddles if the flag is set for any of the input piddles.
Cbscale
Signature: (a(n); b())
Cbscale
Complex inplace multiplaction by real.
Cbscale($a_pdl_cplx,$b_pdl_real);
Cbscale does not process bad values. It will set the bad-value flag of all output piddles if the flag is set for any of the input piddles.
Cconj
Signature: (a(n); [o]c(n))
Cconj
Complex conjugate.
$out_pdl_cplx = Cconj($a_pdl_cplx);
Cconj does not process bad values. It will set the bad-value flag of all output piddles if the flag is set for any of the input piddles.
Cbconj
Signature: (a(n))
Cbconj
Complex inplace conjugate.
Cbconj($a_pdl_cplx);
Cbconj does not process bad values. It will set the bad-value flag of all output piddles if the flag is set for any of the input piddles.
Cexp
Signature: (a(n); [o]c(n))
Cexp
Complex exponentation.
$out_pdl_cplx = Cexp($a_pdl_cplx);
Cexp does not process bad values. It will set the bad-value flag of all output piddles if the flag is set for any of the input piddles.
Cbexp
Signature: (a(n))
Cbexp
Complex inplace exponentation.
$out_pdl_cplx = Cbexp($a_pdl_cplx);
Cbexp does not process bad values. It will set the bad-value flag of all output piddles if the flag is set for any of the input piddles.
Cmod
Signature: (a(n); [o]c())
Cmod
modulus of a complex piddle.
$out_pdl_real = Cmod($a_pdl_cplx);
Cmod does not process bad values. It will set the bad-value flag of all output piddles if the flag is set for any of the input piddles.
Carg
Signature: (a(n); [o]c())
Carg
argument of a complex number.
$out_pdl_real = Carg($a_pdl_cplx);
Carg does not process bad values. It will set the bad-value flag of all output piddles if the flag is set for any of the input piddles.
Cmod2
Signature: (a(n); [o]c())
Cmod2
Returns squared modulus of a complex number.
$out_pdl_real = Cmod2($a_pdl_cplx);
Cmod2 does not process bad values. It will set the bad-value flag of all output piddles if the flag is set for any of the input piddles.
AUTHOR
Copyright (C) 1999 Christian Pellegrin, 2000 Christian Soeller. All rights reserved. There is no warranty. You are allowed to redistribute
this software / documentation under certain conditions. For details, see the file COPYING in the PDL distribution. If this file is
separated from the PDL distribution, the copyright notice should be included in the file.
perl v5.14.2 2012-05-30 FFTW(3pm)