From help-request at octave dot org Fri Feb 18 14:01:22 2005
Subject: Re: C++ using Octave headers, mkoctfile
From: Geraint Paul Bevan <g dot bevan at mech dot gla dot ac dot uk>
To: sct at ucsd dot edu
CC: help at octave dot org
Date: Fri, 18 Feb 2005 20:18:04 +0000

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Steve C. Thompson wrote:

| You are absolutely correct.  But this code snippet was to serve as an
| example only.  Let me simplify the question:
|
| How do I return a complex number from a custom .oct file?
|


Complex is really complex<double>, i.e. the standard C++ complex
template with type double as the data, as can be seen from this line in
octave/oct-cmplx.h:
typedef std::complex<double> Complex;

You form complex numbers using a constructor of the form:
Complex (double realpart, double imagpart)

oct-cmplx.h then goes on to define functions using these Complex data types.


$ cat cplx.cc && mkoctfile cplx.cc && echo [a,b] = cplx | octave -q

#include <octave/oct.h>
DEFUN_DLD (cplx, args, , "simple Complex example")
{
~  static octave_value_list retval;
~  Complex z (0,1);		// real part = 0, imag part = 1
~  retval(0) = z;
~  retval(1) = exp(z);
~  return retval;
}

a = 0 + 1i
b = 0.54030 + 0.84147i


- --
Geraint Bevan
http://homepage.ntlworld.com/geraint.bevan

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