feval

Scilab Function
Last update : 20/12/2004

feval - multiple evaluation

### Calling Sequence

  `[z]=feval(x,y,f)`
  `[z]=feval(x,f)`

### Parameters

- `x,y`: two vectors
- `f`: function or character string (for Fortran or C call)

### Description

Multiple evaluation of a function for one or two arguments of vector type :

  z=feval(x,f)returns the vector `z` defined by `z(i)=f(x(i))`
  z=feval(x,y,f)returns the matrix `z` such as `z(i,j)=f(x(i),y(j))`

`f` is an external (function or routine) accepting on one or two arguments which are supposed to be real. The result returned by `f` can be real or complex. In case of a Fortran call, the function `'f'` must be defined in the subroutine `ffeval.f` (in directory `SCIDIR/routines/default`)

### Examples

    deff('[z]=f(x,y)','z=x^2+y^2');
    feval(1:10,1:5,f)
    deff('[z]=f(x,y)','z=x+%i*y');
    feval(1:10,1:5,f)
    feval(1:10,1:5,'parab')   //See ffeval.f file
    feval(1:10,'parab')
    // For dynamic link (see example ftest in ffeval.f)
    // you can use the link command (the parameters depend on the machine):
    // unix('make ftest.o');link('ftest.o','ftest); feval(1:10,1:5,'ftest')

### See Also

`evstr`, `horner`, `execstr`, `external`, `link`,