/*=================================================================
 * mxcreatecharmatrixfromstr.c
 * 
 * This example takes MATLAB strings as inputs.  It returns a
 * vertically concatenated matrix of the input strings.  If the
 * example is compiled as follows:
 *
 *   mex mxcreatecharmatrixfromstr.c -DSPACE_PADDING
 *
 * it will create a matrix with space padding.  If it is compiled
 * without the flag, the matrix of strings that is created will have
 * NULL padding.
 *
 * This is a MEX-file for MATLAB.  
 * Copyright 1984-2011 The MathWorks, Inc.
 * All rights reserved.
 *=================================================================*/

#include "mex.h"

void
mexFunction(int nlhs,mxArray *plhs[],int nrhs,const mxArray *prhs[])
{
    int i;
    char *str[100];
    
    /* Check for proper number of input and output arguments */
    if (nrhs < 2) {
        mexErrMsgIdAndTxt( "MATLAB:mxcreatecharmatrixfromstr:minrhs",
                "At least two input arguments required.");
    }
    if(nlhs > 1){
        mexErrMsgIdAndTxt( "MATLAB:mxcreatecharmatrixfromstr:maxlhs",
                "Too many output arguments.");
    }
    
    for (i=0; i<nrhs; i++){
        /* Check input to be sure it is of type char. */
        if(!mxIsChar(prhs[i])){
            mexErrMsgIdAndTxt( "MATLAB:mxcreatecharmatrixfromstr:invalidInputType",
                    "Input must be of type char.");
        }
        /* Copy the string data from prhs and place it into str. */
        str[i] = mxArrayToString(prhs[i]);
    }
    
    /* Create a 2-Dimensional string mxArray with NULL padding. */
    plhs[0]= mxCreateCharMatrixFromStrings((mwSize)nrhs, (const char **)str);
    
    /* If compile with -DSPACE_PADDING, convert NULLs to spaces */
#if defined(SPACE_PADDING)
    {
        mwSize j;
        mwSize nelem = mxGetNumberOfElements(plhs[0]);
        mxChar *charData = (mxChar *)mxGetData(plhs[0]);
        for(j=0; j < nelem; j++) {
            if(charData[j] == (mxChar) 0) {
                charData[j] = (mxChar) ' ';
            }
        }
    }
#endif
    /* Free the allocated memory */
    for (i=0; i<nrhs; i++) {
        mxFree(str[i]);
    }
}