idamnjanovic@10: /**************************************************************************
idamnjanovic@10:  *
idamnjanovic@10:  * File name: rowlincomb.c
idamnjanovic@10:  *
idamnjanovic@10:  * Ron Rubinstein
idamnjanovic@10:  * Computer Science Department
idamnjanovic@10:  * Technion, Haifa 32000 Israel
idamnjanovic@10:  * ronrubin@cs
idamnjanovic@10:  *
idamnjanovic@10:  * Last Updated: 21.5.2009
idamnjanovic@10:  *
idamnjanovic@10:  *************************************************************************/
idamnjanovic@10: 
idamnjanovic@10: #include "mex.h"
idamnjanovic@10: 
idamnjanovic@10: 
idamnjanovic@10: /* Input Arguments */
idamnjanovic@10: 
idamnjanovic@10: #define	X_IN	   prhs[0]
idamnjanovic@10: #define A_IN     prhs[1]
idamnjanovic@10: #define ROWS_IN  prhs[2]
idamnjanovic@10: #define COLS_IN  prhs[3]
idamnjanovic@10: 
idamnjanovic@10: 
idamnjanovic@10: /* Output Arguments */
idamnjanovic@10: 
idamnjanovic@10: #define	Y_OUT	plhs[0]
idamnjanovic@10: 
idamnjanovic@10: 
idamnjanovic@10: void mexFunction(int nlhs, mxArray *plhs[],
idamnjanovic@10: int nrhs, const mxArray*prhs[])
idamnjanovic@10: 
idamnjanovic@10: {
idamnjanovic@10:   double *A, *x, *y, *rows, *cols;
idamnjanovic@10:   mwSize m,n,m1,n1,m2,n2,rownum,colnum;
idamnjanovic@10:   mwIndex *row_ids,*col_ids,i,j;
idamnjanovic@10:   int colnumspecified=0;
idamnjanovic@10:   
idamnjanovic@10:   
idamnjanovic@10:   /* Check for proper number of arguments */
idamnjanovic@10:   
idamnjanovic@10:   if (nrhs!=3 && nrhs!=4) {
idamnjanovic@10:     mexErrMsgTxt("Invalid number of input arguments.");
idamnjanovic@10:   } else if (nlhs > 1) {
idamnjanovic@10:     mexErrMsgTxt("Too many output arguments.");
idamnjanovic@10:   }
idamnjanovic@10:   
idamnjanovic@10:   
idamnjanovic@10:   /* Check the input dimensions */
idamnjanovic@10:   
idamnjanovic@10:   m = mxGetM(A_IN);
idamnjanovic@10:   n = mxGetN(A_IN);
idamnjanovic@10:   if (!mxIsDouble(A_IN) || mxIsComplex(A_IN) || mxGetNumberOfDimensions(A_IN)>2) {
idamnjanovic@10:     mexErrMsgTxt("ROWLINCOMB requires that A be a double matrix.");
idamnjanovic@10:   }
idamnjanovic@10:   
idamnjanovic@10:   m1 = mxGetM(ROWS_IN);
idamnjanovic@10:   n1 = mxGetN(ROWS_IN);
idamnjanovic@10:   if (!mxIsDouble(ROWS_IN) || mxIsComplex(ROWS_IN) || (m1!=1 && n1!=1)) {
idamnjanovic@10:     mexErrMsgTxt("ROWLINCOMB requires that ROWS be an index vector of type double.");
idamnjanovic@10:   }
idamnjanovic@10:   rownum = (m1 > n1) ? m1 : n1;   /* the number of rows in the linear combination */
idamnjanovic@10:   
idamnjanovic@10:   m2 = mxGetM(X_IN);
idamnjanovic@10:   n2 = mxGetN(X_IN);
idamnjanovic@10:   if (!mxIsDouble(X_IN) || mxIsComplex(X_IN) || ((m2!=1) && (n2!=1))) {
idamnjanovic@10:     mexErrMsgTxt("ROWLINCOMB requires that X be a double vector.");
idamnjanovic@10:   }
idamnjanovic@10:   
idamnjanovic@10:   if (m2 != rownum && n2 != rownum) {
idamnjanovic@10:     mexErrMsgTxt("The length of X does not match the number of rows in ROWS.");
idamnjanovic@10:   }
idamnjanovic@10:   
idamnjanovic@10:   if (nrhs==4) {
idamnjanovic@10:     m1 = mxGetM(COLS_IN);
idamnjanovic@10:     n1 = mxGetN(COLS_IN);
idamnjanovic@10:     if (!mxIsDouble(COLS_IN) || mxIsComplex(COLS_IN) || (m1!=1 && n1!=1)) {
idamnjanovic@10:       mexErrMsgTxt("ROWLINCOMB requires that COLS be an index vector of type double.");
idamnjanovic@10:     }
idamnjanovic@10:     colnum = (m1 > n1) ? m1 : n1;   /* the number of columns */
idamnjanovic@10:     colnumspecified = 1;
idamnjanovic@10:     cols = mxGetPr(COLS_IN);
idamnjanovic@10:     
idamnjanovic@10:     Y_OUT = mxCreateDoubleMatrix(1, colnum, mxREAL);
idamnjanovic@10:   }
idamnjanovic@10:   else {
idamnjanovic@10:     cols = 0;
idamnjanovic@10:     Y_OUT = mxCreateDoubleMatrix(1, n, mxREAL);
idamnjanovic@10:   }
idamnjanovic@10:   
idamnjanovic@10:   
idamnjanovic@10:   /* Assign pointers to the various parameters */
idamnjanovic@10:   A = mxGetPr(A_IN);
idamnjanovic@10:   rows = mxGetPr(ROWS_IN);
idamnjanovic@10:   x = mxGetPr(X_IN);
idamnjanovic@10:   y = mxGetPr(Y_OUT);
idamnjanovic@10:   
idamnjanovic@10:   
idamnjanovic@10:   /* check row indices */
idamnjanovic@10:   
idamnjanovic@10:   row_ids = (mwIndex*)mxMalloc(rownum*sizeof(mwIndex));
idamnjanovic@10:   
idamnjanovic@10:   for (i=0; i<rownum; ++i) {
idamnjanovic@10:     row_ids[i] = (mwIndex)(rows[i]+0.1)-1;
idamnjanovic@10:     if (row_ids[i]<0 || row_ids[i]>=m) {
idamnjanovic@10:       mexErrMsgTxt("Row index in ROWS is out of range.");
idamnjanovic@10:     }
idamnjanovic@10:   }
idamnjanovic@10:   
idamnjanovic@10:   
idamnjanovic@10:   
idamnjanovic@10:   if (colnumspecified) {
idamnjanovic@10:     
idamnjanovic@10:     /* check column indices */
idamnjanovic@10:     col_ids = (mwIndex*)mxMalloc(colnum*sizeof(mwIndex));
idamnjanovic@10:     
idamnjanovic@10:     for (i=0; i<colnum; ++i) {
idamnjanovic@10:       col_ids[i] = (mwIndex)(cols[i]+0.1)-1;
idamnjanovic@10:       if (col_ids[i]<0 || col_ids[i]>=n) {
idamnjanovic@10:         mexErrMsgTxt("Column index in COLS is out of range.");
idamnjanovic@10:       }
idamnjanovic@10:     }
idamnjanovic@10:     
idamnjanovic@10:     /* Do the actual computation */
idamnjanovic@10:     for (j=0; j<colnum; ++j) {
idamnjanovic@10:       for (i=0; i<rownum; ++i) {
idamnjanovic@10:         y[j] += A[m*col_ids[j]+row_ids[i]]*x[i];
idamnjanovic@10:       }
idamnjanovic@10:     }
idamnjanovic@10:     
idamnjanovic@10:     mxFree(col_ids);
idamnjanovic@10:   }
idamnjanovic@10:   
idamnjanovic@10:   else {
idamnjanovic@10:     
idamnjanovic@10:     /* Do the actual computation */
idamnjanovic@10:     for (j=0; j<n; ++j) {
idamnjanovic@10:       for (i=0; i<rownum; ++i) {
idamnjanovic@10:         y[j] += A[m*j+row_ids[i]]*x[i];
idamnjanovic@10:       }
idamnjanovic@10:     }
idamnjanovic@10:   }
idamnjanovic@10:   
idamnjanovic@10:   
idamnjanovic@10:   mxFree(row_ids);
idamnjanovic@10:   
idamnjanovic@10:   return;
idamnjanovic@10: }