Re: Passing functions as parameters

[etienne grossmann]

From: Dejan Beznec <address@hidden>
#  Hello!
#  I was wondering whether it is possible to pass a valid octave function
#  (e.g. sin(x)+log(x^2+x)) as a parameter to another user-defined
#  function.
#  For example:
#  How to pass f(x)=sin(x)+log(x^2+x) as a parameter to:
#
#  function myfunction(f)
#   ... (perform some calculations with f(x))
#  endfuction
#
#  Making a separate m file for each function to be passed is not
#  acceptable.
#  I am not interested in this particular case, but how to pass a function
#  in general.

  You can pass a string containing the name of the function, and then
use 'feval', as in :

function myfunction(funcname)
  x = 3;
  y = feval(funcname,x) ;
  printf("y = %f\n",y);
end

function z = f(x)
  z=sin(x)+log(x^2+x);
end

myfunction("f")
myfunction("f")

  y = 2.626027

myfunction("cos")

  y = -0.989992


  There is also the 'eval(string)' function, which will evaluate
'string'.

  You may even declare new functions within 'string' :

  eval(["function y = composed_func(x)\n  y = cos( sin( x ) ) ;\nend\n"]);

  Hth,

  Etienne



-----------------------------------------------------------------------
Octave is freely available under the terms of the GNU GPL.

Octave's home on the web:  http://www.che.wisc.edu/octave/octave.html
How to fund new projects:  http://www.che.wisc.edu/octave/funding.html
Subscription information:  http://www.che.wisc.edu/octave/archive.html
-----------------------------------------------------------------------