Let us first discuss what is required to copy a matrix
to a multivector. If we view the matrix as a collection
of columns, this operation is equivalent to copying
each of these columns to the corresponding vector in the
multivector.
However, frequently we will wish to view the matrix
as a collection of rows, and copy each of the rows
to the corresponding vector of the multivector.
If the matrix is entirely owned by one column or
one row of nodes, one can use the
`PLA_Obj_objtype_cast` routine to
cast it into a projected multivector, projected onto
the appropriate mesh dimension (row or column).
After this, the copy can proceed.
If the matrix is not entirely owned by one column
or row of nodes, one can accomplish the same
effect by annotating, but not casting, the matrix to be oriented
like a projected multivector, using a call to
`PLA_Obj_set_orientation`.

In its simplest form, copying a matrix to another matrix requires the global row and column dimensions to match. Since we can annotate a matrix to be oriented like a projected multivector, we also have the ability to transpose a matrix, as the following example illustrates: