| External Interfaces/API Reference | |
Get the real component of an mxArray's first data element
C Syntax
Arguments
array_ptr
Pointer to an mxArray other than a cell mxArray or a structure mxArray.
Returns
The value of the first real (nonimaginary) element of the mxArray. Notice that mxGetScalar returns a double. Therefore, if real elements in the mxArray are stored as something other than doubles, mxGetScalar automatically converts the scalar value into a double. To preserve the original data representation of the scalar, you must cast the return value to the desired data type.
If array_ptr points to a structure mxArray or a cell mxArray, mxGetScalar returns 0.0.
If array_ptr points to a sparse mxArray, mxGetScalar returns the value of the first nonzero real element in the mxArray.
If array_ptr points to an empty mxArray, mxGetScalar returns an indeterminate value.
Description
Call mxGetScalar to get the value of the first real (nonimaginary) element of the mxArray.
In most cases, you call mxGetScalar when array_ptr points to an mxArray containing only one element (a scalar). However, array_ptr can point to an mxArray containing many elements. If array_ptr points to an mxArray containing multiple elements, mxGetScalar returns the value of the first real element. If array_ptr points to a two-dimensional mxArray, mxGetScalar returns the value of the (1,1) element; if array_ptr points to a three-dimensional mxArray, mxGetScalar returns the value of the (1,1,1) element; and so on.
Examples
See timestwoalt.c and xtimesy.c in the refbook subdirectory of the examples directory.
For additional examples, see mxsetdimensions.c in the mx subdirectory of the examples directory; see mexget.c, mexlock.c and mexsettrapflag.c in the mex subdirectory of the examples directory.
See Also
| | mxGetPr | mxGetString | |