Polynomial Symbolic Variable (Scilab gateway) — How to get the symbolic variable name.
Input argument profile:
SciErr getPolyVariableName(void* _pvCtx, int* _piAddress, char* _pstVarName, int* _piVarNameLen)
Scilab environment pointer, pass in "pvApiCtx" provided by api_scilab.h.
Address of the variable.
Return the symbolic varaible name
Return the length of _pstVarName
Error structure where is stored errors messages history and first error number.
int read_poly(char *fname,unsigned long fname_len)
{
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
CheckRhs(1,1);
CheckLhs(1,1);
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 dimmension
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, Rhs + 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
LhsVar(1) = Rhs + 1;
return 0;
}
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