The SYMSQR function takes a square numeric matrix (size ) and compacts the elements from the lower triangle into a column vector ( rows). The matrix is not checked for symmetry, but usually matrix is a symmetric matrix.

The following statement produces the output shown:

   sym=symsqr({1 2, 3 4});

                SYM           3 rows      1 col     (numeric)

                                          1
                                          3
                                          4

Note that the 2 is lost since it is only present in the upper triangle.