Name

Polynomial writing (Scilab gateway) — How to write matrices of polynomials in a gateway.

Calling Sequence

Input argument profile:

SciErr createMatrixOfPoly(void* _pvCtx, int _iVar, char* _pstVarName, int _iRows, int _iCols, int* _piNbCoef, double** _pdblReal)
SciErr createMatrixOfPoly(void* _pvCtx, int _iVar, char* _pstVarName, int _iRows, int _iCols, int* _piNbCoef, double** _pdblReal)

Named variable profile:

SciErr createNamedMatrixOfPoly(void* _pvCtx, char* _pstName, char* _pstVarName, int _iRows, int _iCols, int* _piNbCoef, double** _pdblReal)
SciErr createNamedComplexMatrixOfPoly(void* _pvCtx, char* _pstName, char* _pstVarName, int _iRows, int _iCols, int* _piNbCoef, double** _pdblReal, double** _pdblImg)

Parameters

_pvCtx

Scilab environment pointer, pass in "pvApiCtx" provided by api_scilab.h.

_iVar

Position in the Scilab memory where you want to put the variable

_pstName

Name of the variable for "named" functions.

_pstVarName

Variable name in polynomials (Scilab5: 4 characters max)

_iRows

Number of rows of the new variable

_iCols

Numbers of columns of the new variable

_piNbCoef

Number of coefficient for each polynomial.

_pdblReal

Address of array of double* with real part of coefficient (size: _iCols * _iRows)

_pdblImg

Address of array of double* with imaginary part of coefficient (size: _iCols * _iRows)

SciErr

Error structure where is stored errors messages history and first error number.

Description

This help describes how matrix of polynomials can be handled through the Scilab API.

Gateway Source

     
int write_poly(char *fname,unsigned long fname_len)
{
    SciErr sciErr;
    //output variable info : polinomial matrix 2 x 4
    //[ x + 2                   x^2 - 4x + 5    4x^3 - 14x^2 + 18 ;
    //  2x^3 - 12x^2 + 64       1               8x^5 + 32x^3]
    int iRows               = 2;
    int iCols               = 3;

    //varname "x"
    char pstVarName[2]      = {"x"};

    //coeficient array
    int piNbCoef[6]         = {2,4,3,1,4,6};

    //data array
    double *pdblReal[6]     = {0};
    double pdblPoly0[2]     = {2,1};
    double pdblPoly1[4]     = {64,0,-12,2};
    double pdblPoly2[3]     = {5,-4,1};
    double pdblPoly3[1]     = {1};
    double pdblPoly4[4]     = {18,0,-14,4};
    double pdblPoly5[6]     = {0,0,0,32,0,8};

    pdblReal[0]             = pdblPoly0;
    pdblReal[1]             = pdblPoly1;
    pdblReal[2]             = pdblPoly2;
    pdblReal[3]             = pdblPoly3;
    pdblReal[4]             = pdblPoly4;
    pdblReal[5]             = pdblPoly5;

    sciErr = createMatrixOfPoly(pvApiCtx, Rhs + 1, pstVarName, iRows, iCols, piNbCoef, pdblReal);
    if(sciErr.iErr)
    {
        printError(&sciErr, 0);
        return 0;
    }

    //assign allocated variables to Lhs position
    LhsVar(1) = Rhs + 1;
    return 0;
}

Scilab test script

 
p_ref = [2 5 18 1 -4 0 0 1 -14 0 0 4 0 0 0 0 0 0;64 1 0 0 0 0 -12 0 0 2 0 32 0 0 0 0 0 8];
l = list();
a = write_poly();
p = coeff(a);
if or(p <> p_ref) then error("failed"), end