fort — Fortran or C user routines call

// 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)

- "ident"
string.

- xi
real matrix or string

- pxi, pyi
integers

- txi, tyi
character string

`"d"`

,`"r"`

,`"i"`

or`"c"`

.

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");