+static unsigned matrix_rank()
+{
+ unsigned result = 0;
+ symbol x("x"), y("y");
+ matrix m(3,3);
+
+ // the zero matrix always has rank 0
+ if (m.rank() != 0) {
+ clog << "The rank of " << m << " was not computed correctly." << endl;
+ ++result;
+ }
+
+ // a trivial rank one example
+ m = 1, 0, 0,
+ 2, 0, 0,
+ 3, 0, 0;
+ if (m.rank() != 1) {
+ clog << "The rank of " << m << " was not computed correctly." << endl;
+ ++result;
+ }
+
+ // an example from Maple's help with rank two
+ m = x, 1, 0,
+ 0, 0, 1,
+ x*y, y, 1;
+ if (m.rank() != 2) {
+ clog << "The rank of " << m << " was not computed correctly." << endl;
+ ++result;
+ }
+
+ // the 3x3 unit matrix has rank 3
+ m = ex_to<matrix>(unit_matrix(3,3));
+ if (m.rank() != 3) {
+ clog << "The rank of " << m << " was not computed correctly." << endl;
+ ++result;
+ }
+
+ return result;
+}
+