Polynomial Symbolic Variable (Scilab gateway)
How to get the symbolic variable name.
Syntax
Input argument profile:
SciErr getPolyVariableName(void* _pvCtx, int* _piAddress, char* _pstVarName, int* _piVarNameLen)
Arguments
- _pvCtx
Scilab environment pointer, pass in "pvApiCtx" provided by api_scilab.h.
- _piAddress
Address of the variable.
- _pstVarName
Return the symbolic variable name
- _piVarNameLen
Return the length of _pstVarName
- SciErr
Error structure where is stored errors messages history and first error number.
Description
This help describes how to get the symbolic variable name.
Gateway Source
#include "api_scilab.h" int read_poly(char *fname,void* pvApiCtx) { SciErr sciErr; int i,j; //variable info int iRows = 0; int iCols = 0; int iVarLen = 0; int* piAddr = NULL; int* piNbCoef = NULL; double** pdblReal = NULL; double** pdblImg = NULL; char* pstVarname = NULL; //check input and output arguments CheckInputArgument(pvApiCtx, 1, 1); CheckOutputArgument(pvApiCtx, 0, 1); sciErr = getVarAddressFromPosition(pvApiCtx, 1, &piAddr); if(sciErr.iErr) { printError(&sciErr, 0); return 0; } if(isVarComplex(pvApiCtx, piAddr) == FALSE) { //Error return 0; } //get variable name length sciErr = getPolyVariableName(pvApiCtx, piAddr, NULL, &iVarLen); if(sciErr.iErr) { printError(&sciErr, 0); return 0; } //alloc buff to receive variable name pstVarname = (char*)malloc(sizeof(char) * (iVarLen + 1));//1 for null termination //get variable name sciErr = getPolyVariableName(pvApiCtx, piAddr, pstVarname, &iVarLen); if(sciErr.iErr) { printError(&sciErr, 0); return 0; } //First call: retrieve dimension sciErr = getComplexMatrixOfPoly(pvApiCtx, piAddr, &iRows, &iCols, NULL, NULL, NULL); if(sciErr.iErr) { printError(&sciErr, 0); return 0; } //alloc array of coefficient piNbCoef = (int*)malloc(sizeof(int) * iRows * iCols); //Second call: retrieve coefficient sciErr = getComplexMatrixOfPoly(pvApiCtx, piAddr, &iRows, &iCols, piNbCoef, NULL, NULL); if(sciErr.iErr) { printError(&sciErr, 0); return 0; } //alloc arrays of data pdblReal = (double**)malloc(sizeof(double*) * iRows * iCols); pdblImg = (double**)malloc(sizeof(double*) * iRows * iCols); for(i = 0 ; i < iRows * iCols ; i++) { pdblReal[i] = (double*)malloc(sizeof(double) * piNbCoef[i]); pdblImg[i] = (double*)malloc(sizeof(double) * piNbCoef[i]); } //Third call: retrieve data sciErr = getComplexMatrixOfPoly(pvApiCtx, piAddr, &iRows, &iCols, piNbCoef, pdblReal, pdblImg); if(sciErr.iErr) { printError(&sciErr, 0); return 0; } //Do something with Data //Invert polynomials in the matrix and invert coefficients for(i = 0 ; i < (iRows * iCols) / 2 ; i++) { int iPos1 = iRows * iCols - 1 - i; double* pdblSave = NULL; int iNbCoefSave = 0; //switch array of coefficient pdblSave = pdblReal[i]; pdblReal[i] = pdblReal[iPos1]; pdblReal[iPos1] = pdblSave; pdblSave = pdblImg[i]; pdblImg[i] = pdblImg[iPos1]; pdblImg[iPos1] = pdblSave; //switch number of coefficient iNbCoefSave = piNbCoef[i]; piNbCoef[i] = piNbCoef[iPos1]; piNbCoef[iPos1] = iNbCoefSave; } //switch coefficient for(i = 0 ; i < iRows * iCols ; i++) { for(j = 0 ; j < piNbCoef[i] /2 ; j++) { int iPos2 = piNbCoef[i] - 1 - j; double dblVal = pdblReal[i][j]; pdblReal[i][j] = pdblReal[i][iPos2]; pdblReal[i][iPos2] = dblVal; dblVal = pdblImg[i][j]; pdblImg[i][j] = pdblImg[i][iPos2]; pdblImg[i][iPos2] = dblVal; } } sciErr = createComplexMatrixOfPoly(pvApiCtx, nbInputArgument(pvApiCtx) + 1, pstVarname, iRows, iCols, piNbCoef, pdblReal, pdblImg); if(sciErr.iErr) { printError(&sciErr, 0); return 0; } //free OS memory free(pstVarname); free(piNbCoef); for(i = 0 ; i < iRows * iCols ; i++) { free(pdblReal[i]); free(pdblImg[i]); } free(pdblReal); free(pdblImg); //assign allocated variables to Lhs position AssignOutputVariable(pvApiCtx, 1) = nbInputArgument(pvApiCtx) + 1; return 0; }
Scilab test script
coeff1 = [ .. 29*%i,22*%i,16*%i,11*%i,7*%i,30,23,17,12,8,-31*%i,-24*%i,-18*%i,-13*%i,-9*%i,32,25,19,14,10,-33*%i,-26*%i,-20*%i,-15*%i,0,34,27,21,0,0,0,-28*%i,0,0,0,36-35*%i,0,0,0,0; .. 4*%i,2*%i,%i,22,16,5,-3,0,-23*%i,-17*%i,-6*%i,0,0,24,18,0,0,0,-25*%i,-19*%i,0,0,0,26,20,0,0,0,-27*%i,-21*%i,0,0,0,28,0,0,0,0,0,0; .. 11,7,4,2,1,-12*%i,-8*%i,-5*%i,3*%i,0,13,9,6,0,0,-14*%i,-10*%i,0,0,0,15,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]; x = poly(0, "x"); p1 = 1; p2 = 2 * x + 3 * %i; p3 = 4 * x**2 - 5 * %i * x + 6; p4 = 7 * x**3 - 8 * %i * x**2 + 9 * x - 10 * %i; p5 = 11 * x**4 - 12 * %i * x**3 + 13 * x**2 - 14 * %i * x + 15; p6 = 16 * x**5 - 17 * %i * x**4 + 18 * x**3 - 19 * %i * x**2 + 20 * x - 21 * %i; p7 = 22 * x**6 - 23 * %i * x**5 + 24 * x**4 - 25 * %i * x**3 + 26 * x**2 - 27 * %i * x + 28; p8 = %i; p9 = 2 * %i * x - 3; p10 = 4 * %i * x**2 + 5 * x - 6 * %i; p11 = 7 * %i * x**3 + 8 * x**2 - 9 * %i * x + 10; p12 = 11 * %i * x**4 + 12 * x**3 - 13 * %i * x**2 + 14 * x - 15 * %i; p13 = 16 * %i * x**5 + 17 * x**4 - 18 * %i * x**3 + 19 * x**2 - 20 * %i * x + 21; p14 = 22 * %i * x**6 + 23 * x**5 - 24 * %i * x**4 + 25 * x**3 - 26 * %i * x**2 + 27 * x - 28 * %i; p15 = 29 * %i * x**7 + 30 * x**6 - 31 * %i * x**5 + 32 * x**4 - 33 * %i * x**3 + 34 * x**2 - 35 * %i + 36; p = [p1, p2, p3, p4, p5 ; p6, p7, p8, p9 ,p10 ; p11, p12, p13, p14, p15]; p1 = read_poly(p); coeff2 = coeff(p1); if or(coeff2 <> coeff1) then error("failed"), end
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