MATLAB: Boolean matrix in mex file

doublelogicmex

Hello everyone,

I'm trying to read a logical matrix in a mex file with matlab. The way I usally do for reading matrices in matlab is:

double *var = mxGetPr(prhs[0]);

If the variable in matlab is logic, I get weird results in C++, but if I try to initialize var as boolean:

bool *var = mxGetPr(prhs[0]);

I get:

error C2440: 'initializing' : cannot convert from 'double *' to 'bool *'

The only solution I've found, for the moment, is passing the logical matrix as double to the mex routine, but I'd prefer reading the boolean matrix instead.

How can I do that?

Alessandro.

Best Answer

Hi Alessandro,

use mxGetLogicals instead of mxGetPr ...

Titus

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MATLAB: Inverse matrix in mexFunction

The copy of the data to the output would be faster using memcpy:

plhs[0] = mxCreateDoubleMatrix(outputRowLen, outputColLen, mxREAL); 
memcpy(mxGetPr(plhs[0]), Sigma_Psi_inv_t, 
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But you can use the data of the output array directly:

plhs[0] = mxCreateDoubleMatrix(rowSigma_Psi, colSigma_Psi, mxREAL); 
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Do not use int for LAPACK calls in an 64 bit environment. Use mwSignedIndex instead, which is a 64 bit integer.

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x and y are pointers, so you need to dereference them to get at the double values they point to. So your code should be:

plhs[0] = mxCreateDoubleScalar (*x * *y);

Best Answer

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