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/operators/Sparse-perm-op-defs.h
+++ b/liboctave/operators/Sparse-perm-op-defs.h
@@ -67,17 +67,7 @@
       return SM ();
     }
 
-  if (p.is_row_perm ())
-    {
-      // Form the column permutation and then call the colpm_sm routine.
-      const octave_idx_type *prow = p.pvec ().data ();
-      OCTAVE_LOCAL_BUFFER (octave_idx_type, pcol, nr);
-      for (octave_idx_type i = 0; i < nr; ++i)
-        pcol[prow[i]] = i;
-      return octinternal_do_mul_colpm_sm (pcol, a);
-    }
-  else
-    return octinternal_do_mul_colpm_sm (p.pvec ().data (), a);
+  return octinternal_do_mul_colpm_sm (p.col_perm_vec ().data (), a);
 }
 
 template <typename SM>
@@ -163,10 +153,7 @@
       return SM ();
     }
 
-  if (p.is_row_perm ())
-    return octinternal_do_mul_sm_rowpm (a, p.pvec ().data ());
-  else
-    return octinternal_do_mul_sm_colpm (a, p.pvec ().data ());
+  return octinternal_do_mul_sm_colpm (a, p.col_perm_vec ().data ());
 }
 
 #endif // octave_Sparse_perm_op_defs_h