Name

Boolean sparse reading (Scilab gateway) — How to read boolean sparse in a gateway.

Calling Sequence

Input argument profile:

SciErr getBooleanSparseMatrix(void* _pvCtx, int* _piAddress, int* _piRows, int* _piCols, int* _piNbItem, int** _piNbItemRow, int** _piColPos)

Named variable profile:

SciErr readNamedBooleanSparseMatrix(void* _pvCtx, char* _pstName, int* _piRows, int* _piCols, int* _piNbItem, int* _piNbItemRow, int* _piColPos)

Parameters

_pvCtx

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

_piAddress

Address of the Scilab variable.

_pstName

Name of the variable for "named" functions.

_piRows

Return number of rows of the variable.

_piCols

Return number of columns of the variable.

_piNbItem

Return number of non zero value.

_piNbItemRow

Return number of item in each rows (size: _iRows).

_piColPos

Return column position for each item (size: _iNbItem).

SciErr

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

Description

This help describes how to read boolean sparse.

Gateway Source

             
int read_write_bsparse(char *fname,unsigned long fname_len)
{
    SciErr sciErr;
    int i                   = 0;
    int j                   = 0;
    int k                   = 0;

    //first variable info : real matrix of double
    int iRows               = 0;
    int iCols               = 0;
    int *piAddr             = NULL;
    int iNbItem             = 0;
    int* piNbItemRow        = NULL;
    int* piColPos           = NULL;

    int iCol                = 0;
    int iNewCol             = 0;

    int iNewItem            = 0;
    int* piNewRow           = NULL;
    int* piNewCol           = NULL;
    

    //check input and output arguments
    CheckRhs(1,1);
    CheckLhs(1,1);


    //get variable address of the first input argument
    sciErr = getVarAddressFromPosition(pvApiCtx, 1, &piAddr);
    if(sciErr.iErr)
    {
        printError(&sciErr, 0);
        return 0;
    }

    //get size and data from Scilab memory
    sciErr = getBooleanSparseMatrix(pvApiCtx, piAddr, &iRows, &iCols, &iNbItem, &piNbItemRow, &piColPos);
    if(sciErr.iErr)
    {
        printError(&sciErr, 0);
        return 0;
    }

    //Do something with data
    //convert %T -> %F and %F -> %T

    iNewItem = (iRows * iCols) - iNbItem;
    piNewRow = (int*)MALLOC(sizeof(int) * iRows);
    piNewCol = (int*)MALLOC(sizeof(int) * iNewItem);

    for(i = 0 ; i < iRows ; i++)
    {
        piNewRow[i] = iCols - piNbItemRow[i];
        for(j = 0 ; j < iCols ; j++)
        {
            int iFind = 0;
            for(k = 0 ; k < piNbItemRow[i] ; k++)
            {
                if(piColPos[iCol + k] == (j + 1))
                {
                    iFind = 1;
                    break;
                }
            }
            if(iFind == 0)
            {
                piNewCol[iNewCol++] = (j + 1);
            }
        }
        iCol += piNbItemRow[i];
    }

    sciErr = createBooleanSparseMatrix(pvApiCtx, Rhs + 1, iRows, iCols, iNewItem, piNewRow, piNewCol);
    if(sciErr.iErr)
    {
        printError(&sciErr, 0);
        return 0;
    }

    LhsVar(1) = Rhs + 1;
    return 0;
}

Scilab test script

             
a = sparse([%t, %f, %t ; %f, %t, %f ; %t, %f, %t]);
a_ref = sparse([%f, %t, %f ; %t, %f, %t ; %f, %t, %f]);

b = read_write_bsparse(a);
if or(b <> a_ref) then error("failed");end