Mercurial > hg > smallbox
view util/ksvd utils/rowlincomb.c @ 207:233e75809e4a luisf_dev
Accelerated the code for LGD and optimal grandient descent
author | bmailhe |
---|---|
date | Wed, 21 Mar 2012 14:12:25 +0000 |
parents | c3eca463202d |
children |
line wrap: on
line source
/************************************************************************** * * File name: rowlincomb.c * * Ron Rubinstein * Computer Science Department * Technion, Haifa 32000 Israel * ronrubin@cs * * Last Updated: 21.5.2009 * *************************************************************************/ #include "mex.h" /* Input Arguments */ #define X_IN prhs[0] #define A_IN prhs[1] #define ROWS_IN prhs[2] #define COLS_IN prhs[3] /* Output Arguments */ #define Y_OUT plhs[0] void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray*prhs[]) { double *A, *x, *y, *rows, *cols; mwSize m,n,m1,n1,m2,n2,rownum,colnum; mwIndex *row_ids,*col_ids,i,j; int colnumspecified=0; /* Check for proper number of arguments */ if (nrhs!=3 && nrhs!=4) { mexErrMsgTxt("Invalid number of input arguments."); } else if (nlhs > 1) { mexErrMsgTxt("Too many output arguments."); } /* Check the input dimensions */ m = mxGetM(A_IN); n = mxGetN(A_IN); if (!mxIsDouble(A_IN) || mxIsComplex(A_IN) || mxGetNumberOfDimensions(A_IN)>2) { mexErrMsgTxt("ROWLINCOMB requires that A be a double matrix."); } m1 = mxGetM(ROWS_IN); n1 = mxGetN(ROWS_IN); if (!mxIsDouble(ROWS_IN) || mxIsComplex(ROWS_IN) || (m1!=1 && n1!=1)) { mexErrMsgTxt("ROWLINCOMB requires that ROWS be an index vector of type double."); } rownum = (m1 > n1) ? m1 : n1; /* the number of rows in the linear combination */ m2 = mxGetM(X_IN); n2 = mxGetN(X_IN); if (!mxIsDouble(X_IN) || mxIsComplex(X_IN) || ((m2!=1) && (n2!=1))) { mexErrMsgTxt("ROWLINCOMB requires that X be a double vector."); } if (m2 != rownum && n2 != rownum) { mexErrMsgTxt("The length of X does not match the number of rows in ROWS."); } if (nrhs==4) { m1 = mxGetM(COLS_IN); n1 = mxGetN(COLS_IN); if (!mxIsDouble(COLS_IN) || mxIsComplex(COLS_IN) || (m1!=1 && n1!=1)) { mexErrMsgTxt("ROWLINCOMB requires that COLS be an index vector of type double."); } colnum = (m1 > n1) ? m1 : n1; /* the number of columns */ colnumspecified = 1; cols = mxGetPr(COLS_IN); Y_OUT = mxCreateDoubleMatrix(1, colnum, mxREAL); } else { cols = 0; Y_OUT = mxCreateDoubleMatrix(1, n, mxREAL); } /* Assign pointers to the various parameters */ A = mxGetPr(A_IN); rows = mxGetPr(ROWS_IN); x = mxGetPr(X_IN); y = mxGetPr(Y_OUT); /* check row indices */ row_ids = (mwIndex*)mxMalloc(rownum*sizeof(mwIndex)); for (i=0; i<rownum; ++i) { row_ids[i] = (mwIndex)(rows[i]+0.1)-1; if (row_ids[i]<0 || row_ids[i]>=m) { mexErrMsgTxt("Row index in ROWS is out of range."); } } if (colnumspecified) { /* check column indices */ col_ids = (mwIndex*)mxMalloc(colnum*sizeof(mwIndex)); for (i=0; i<colnum; ++i) { col_ids[i] = (mwIndex)(cols[i]+0.1)-1; if (col_ids[i]<0 || col_ids[i]>=n) { mexErrMsgTxt("Column index in COLS is out of range."); } } /* Do the actual computation */ for (j=0; j<colnum; ++j) { for (i=0; i<rownum; ++i) { y[j] += A[m*col_ids[j]+row_ids[i]]*x[i]; } } mxFree(col_ids); } else { /* Do the actual computation */ for (j=0; j<n; ++j) { for (i=0; i<rownum; ++i) { y[j] += A[m*j+row_ids[i]]*x[i]; } } } mxFree(row_ids); return; }