make all permutation matrices column permutations (bug #42418) Making all permutation matrices column permutations allows permutation matrices to be iterated over in column-major order just like any other matrix. * PermMatrix.h, PermMatrix.cc (PermMatrix::_colp): Delete member variable and all uses. (PermMatrix::transpose): Create new matrix with internal representation flipped. (PermMatrix::pos_power): New function. (PermMatrix::eye): Call the one-argument constructor which already defaults to the identity matrix. (PermMatrix::is_col_perm): Unconditionally return true. (PermMatrix::is_row_perm): Unconditionally return false. (PermMatrix::data, PermMatrix::fortran_vec, PermMatrix::pvec): Delete. (PermMatrix::col_perm_vec): New function. * lu.cc: New test. * base-lu.cc (base_lu<lu_type>::base_lu): Call transpose in ipvt initialization. * find.cc, kron.cc, pr-output.cc, ov-perm.cc, PermMatrix.cc, PermMatrix.h, Sparse.cc, dMatrix.cc, fMatrix.cc, CmplxQRP.cc, base-lu.cc, dbleQRP.cc, fCmplxQRP.cc, floatQRP.cc, Sparse-perm-op-defs.h, mx-op-defs.h: Adapt to PermMatrix changes.

--- a/liboctave/array/fMatrix.cc
+++ b/liboctave/array/fMatrix.cc
@@ -259,14 +259,10 @@
 FloatMatrix::FloatMatrix (const PermMatrix& a)
   : MArray<float> (a.dims (), 0.0)
 {
-  const Array<octave_idx_type> ia (a.pvec ());
+  const Array<octave_idx_type> ia (a.col_perm_vec ());
   octave_idx_type len = a.rows ();
-  if (a.is_col_perm ())
-    for (octave_idx_type i = 0; i < len; i++)
-      elem (ia(i), i) = 1.0;
-  else
-    for (octave_idx_type i = 0; i < len; i++)
-      elem (i, ia(i)) = 1.0;
+  for (octave_idx_type i = 0; i < len; i++)
+    elem (ia(i), i) = 1.0;
 }
 
 // FIXME: could we use a templated mixed-type copy function here?