fort

Fortran or C user routines call

Calling Sequence

// long form 'out' is present
[y1,...,yk] = fort("ident",x1,px1,"tx1",...,xn,pxn,"txn","out",[ny1,my1],py1,"ty1",...,[nyl,myl],pyl,"tyl")
// short form : no 'out' parameter
[y1,....,yk] = fort("ident",x1,...,xn)

Arguments

:”ident” string. : :xi real matrix or string : :pxi, pyi integers : :txi, tyi character string “d”, “r”, “i” or “c”. :

Description

Interactive call of Fortran (or C) user program from Scilab. The routine must be previously linked with Scilab. This link may be done:

• with Scilab ” link” command (dynamic link) during the Scilab session.(see link)

There are two forms of calling syntax, a short one and a long one. The short one will give faster code and an easier calling syntax but one has to write a small (C or Fortran) interface in order to make the short form possible. The long one make it possible to call a Fortran routine (or a C one) whitout modification of the code but the syntax is more complex and the interpreted code slower.

The meaning of each parameter is described now:

:”ident” is the name of the called subroutine. : :x1,...,xn are input variables (real matrices or strings) sent to

the routine,

: :px1,...,pxn are the respective positions of these variables in the

calling sequence of the routine “ident” and

: :tx1,...,txn are their types ( “r”, “i”, “d” and “c” for

real (float) , integer, double precision and strings)

: :”out” is a keyword used to separate input variables from output

variables. when this key word is present it is assumes that the long form will be used and when it is not prsent, the short form is used.

: :[ny1, my1] are the size (number of rows and columns. For ‘c’

arguments, m1*n1 is the number of charaters ) of output variables and

: :py1, ... are the positions of output variables (possibly equal to

pxi ) in the calling sequence of the routine. The pyi‘s integers must be in increasing order.

: :”ty1”, ... are the Fortran types of output variables. The k first

output variables are put in y1,..., yk.

:

If an output variable coincides with an input variable (i.e. pyi=pxj ) one can pass only its position pyi . The size and type of yi are then the same as those of xi. If an output variable coincides with an input variable and one specify the dimensions of the output variable [myl,nyl] must follow the compatibility condition mxk*nxk >= myl*nyl.

For example the following program:

subroutine foof(c,a,b,n,m)
  integer n,m
  `double`_ precision a(*),b,c(*)
  do 10 i=1,m*n
    c(i) = `sin`_(a(i))+b
  10 continue
end

`link`_("foof"+`getdynlibext`_(),"foof")
a=[1,2,3;4,5,6];b= %pi;
[m,n]=`size`_(a);
// Inputs:
// a is in position 2 and double
// b                3     double
// n                4     integer
// m                5     integer
// Outputs:
// c is in position 1 and double with size [m,n]
c=fort("foof",a,2,"d",b,3,"d",n,4,"i",m,5,"i","out",[m,n],1,"d");

returns the matrix c=2*a+b.

The same example coded in C:

void fooc(c,a,b,m,n)
`double`_ a[],*b,c[];
`int`_ *m,*n;
{
   `double`_ sin();
   `int`_ i;
   for ( i =0 ; i < (*m)*(*n) ; i++)
       c[i] = `sin`_(a[i]) + *b;
}

`link`_("fooc"+`getdynlibext`_(),"fooc","C") // note the third argument
a=[1,2,3;4,5,6];b= %pi;
[m,n]=`size`_(a);
c=fort("fooc",a,2,"d",b,3,"d",m,4,"i",n,5,"i","out",[m,n],1,"d");

See Also

• call Fortran or C user routines call
• link dynamic linker
• c_link check if symbol loaded with dynamic link
• intersci Scilab tool to interface C or Fortran functions with scilab. Deprecated: Please use SWIG
• addinter new functions interface dynamic link at run time.
• api_scilab api_scilab is the Scilab interface to read/write data from/to Scilab memory