3.2.1 Function Structure

Function structure must obey the following format

function [y1,...,yn]=foo(x1,...,xm)
   .
   .
   .

where foo is the function name, the xi are the $m$ input arguments of the function, the yj are the $n$ output arguments from the function, and the three vertical dots represent the list of instructions performed by the function. An example of a function which calculates $k!$ is as follows

function [x]=fact(k)
  k=int(k)
  if k<1 then k=1,end
  x=1;
  for j=1:k,x=x*j;end
endfunction

If this function is contained in a file called fact.sci the function must be ``loaded'' into Scilab by the exec or getf command and before it can be used:

--> exists('fact')
 ans       =
 
    0.  
 
--> exec('../macros/fact.sci',-1);
 
--> exists('fact')
 ans       =
 
    1.  
 
--> x=fact(5)
 x         =
 
    120.

In the above Scilab session, the command exists indicates that fact is not in the environment (by the 0 answer to exist). The function is loaded into the environment using exec and now exists indicates that the function is there (the $1$ answer). The example calculates $5!$.