Determine whether input is sparse array
Logical 1 (true) if pm points to a sparse mxArray, and logical 0 (false) otherwise. A false return value means that pm points to a full mxArray or that pm does not point to a legal mxArray.
Use mxIsSparse to determine whether pm points to a sparse mxArray. Many routines (for example, mxGetIr and mxGetJc) require a sparse mxArray as input.
See the following examples in matlabroot/extern/examples/refbook.
See the following examples in matlabroot/extern/examples/mx.