Mercurial > hg > octave-lyh
changeset 15304:4663cc835c65 stable
Special-case removing rows or columns from empty sparse matrices
* Sparse.cc (Sparse<T>::delete_elements): Don't attempt to preserve
elements if nnz = 0; simply reshape if number of rows or columns is zero.
author | John W. Eaton <jwe@octave.org> |
---|---|
date | Thu, 21 Jun 2012 14:42:05 -0400 |
parents | f2e72944847b |
children | b135f013679e 197774b411ec |
files | liboctave/Sparse.cc |
diffstat | 1 files changed, 56 insertions(+), 25 deletions(-) [+] |
line wrap: on
line diff
--- a/liboctave/Sparse.cc +++ b/liboctave/Sparse.cc @@ -1240,16 +1240,31 @@ gripe_del_index_out_of_range (false, idx_j.extent (nc), nc); else if (idx_j.is_cont_range (nc, lb, ub)) { - const Sparse<T> tmp = *this; - octave_idx_type lbi = tmp.cidx(lb), ubi = tmp.cidx(ub), new_nz = nz - (ubi - lbi); - *this = Sparse<T> (nr, nc - (ub - lb), new_nz); - copy_or_memcpy (lbi, tmp.data (), data ()); - copy_or_memcpy (lbi, tmp.ridx (), ridx ()); - copy_or_memcpy (nz - ubi, tmp.data () + ubi, xdata () + lbi); - copy_or_memcpy (nz - ubi, tmp.ridx () + ubi, xridx () + lbi); - copy_or_memcpy (lb, tmp.cidx () + 1, cidx () + 1); - mx_inline_sub (nc - ub, xcidx () + lb + 1, - tmp.cidx () + ub + 1, ubi - lbi); + if (lb == 0 && ub == nc) + { + // Delete all rows and columns. + *this = Sparse<T> (nr, 0); + } + else if (nz == 0) + { + // No elements to preserve; adjust dimensions. + *this = Sparse<T> (nr, nc - (ub - lb)); + } + else + { + const Sparse<T> tmp = *this; + octave_idx_type lbi = tmp.cidx(lb), ubi = tmp.cidx(ub), + new_nz = nz - (ubi - lbi); + + *this = Sparse<T> (nr, nc - (ub - lb), new_nz); + copy_or_memcpy (lbi, tmp.data (), data ()); + copy_or_memcpy (lbi, tmp.ridx (), ridx ()); + copy_or_memcpy (nz - ubi, tmp.data () + ubi, xdata () + lbi); + copy_or_memcpy (nz - ubi, tmp.ridx () + ubi, xridx () + lbi); + copy_or_memcpy (lb, tmp.cidx () + 1, cidx () + 1); + mx_inline_sub (nc - ub, xcidx () + lb + 1, + tmp.cidx () + ub + 1, ubi - lbi); + } } else *this = index (idx_i, idx_j.complement (nc)); @@ -1262,24 +1277,40 @@ gripe_del_index_out_of_range (false, idx_i.extent (nr), nr); else if (idx_i.is_cont_range (nr, lb, ub)) { - // This is more memory-efficient than the approach below. - const Sparse<T> tmpl = index (idx_vector (0, lb), idx_j); - const Sparse<T> tmpu = index (idx_vector (ub, nr), idx_j); - *this = Sparse<T> (nr - (ub - lb), nc, tmpl.nnz () + tmpu.nnz ()); - for (octave_idx_type j = 0, k = 0; j < nc; j++) + if (lb == 0 && ub == nr) + { + // Delete all rows and columns. + *this = Sparse<T> (0, nc); + } + else if (nz == 0) { - for (octave_idx_type i = tmpl.cidx(j); i < tmpl.cidx(j+1); i++) + // No elements to preserve; adjust dimensions. + *this = Sparse<T> (nr - (ub - lb), nc); + } + else + { + // This is more memory-efficient than the approach below. + const Sparse<T> tmpl = index (idx_vector (0, lb), idx_j); + const Sparse<T> tmpu = index (idx_vector (ub, nr), idx_j); + *this = Sparse<T> (nr - (ub - lb), nc, + tmpl.nnz () + tmpu.nnz ()); + for (octave_idx_type j = 0, k = 0; j < nc; j++) { - xdata(k) = tmpl.data(i); - xridx(k++) = tmpl.ridx(i); + for (octave_idx_type i = tmpl.cidx(j); i < tmpl.cidx(j+1); + i++) + { + xdata(k) = tmpl.data(i); + xridx(k++) = tmpl.ridx(i); + } + for (octave_idx_type i = tmpu.cidx(j); i < tmpu.cidx(j+1); + i++) + { + xdata(k) = tmpu.data(i); + xridx(k++) = tmpu.ridx(i) + lb; + } + + xcidx(j+1) = k; } - for (octave_idx_type i = tmpu.cidx(j); i < tmpu.cidx(j+1); i++) - { - xdata(k) = tmpu.data(i); - xridx(k++) = tmpu.ridx(i) + lb; - } - - xcidx(j+1) = k; } } else