sets a subtensor element in an MTensor.
- Used in C/C++ code in a library function called from Mathematica.
- Uses the same numbering scheme as Mathematica parts, i.e. the first element is 1.
- The array is assumed to have length at least equal to .
- A nonzero error code value will be returned if the element does not exist, if the rank of is not equal to plus the rank of , if the types of and are not the same, or if the dimensions are inconsistent.