Mercurial > octave-nkf
view libinterp/corefcn/filter.cc @ 17787:175b392e91fe
Use GNU style coding conventions for code in libinterp/
* libinterp/corefcn/Cell.h, libinterp/corefcn/__contourc__.cc,
libinterp/corefcn/__dispatch__.cc, libinterp/corefcn/__lin_interpn__.cc,
libinterp/corefcn/__pchip_deriv__.cc, libinterp/corefcn/__qp__.cc,
libinterp/corefcn/balance.cc, libinterp/corefcn/besselj.cc,
libinterp/corefcn/betainc.cc, libinterp/corefcn/bitfcns.cc,
libinterp/corefcn/bsxfun.cc, libinterp/corefcn/c-file-ptr-stream.cc,
libinterp/corefcn/c-file-ptr-stream.h, libinterp/corefcn/cellfun.cc,
libinterp/corefcn/colloc.cc, libinterp/corefcn/comment-list.h,
libinterp/corefcn/conv2.cc, libinterp/corefcn/daspk.cc,
libinterp/corefcn/dasrt.cc, libinterp/corefcn/dassl.cc,
libinterp/corefcn/data.cc, libinterp/corefcn/debug.cc,
libinterp/corefcn/defaults.cc, libinterp/corefcn/defaults.in.h,
libinterp/corefcn/defun-int.h, libinterp/corefcn/defun.cc,
libinterp/corefcn/det.cc, libinterp/corefcn/dirfns.cc,
libinterp/corefcn/display.cc, libinterp/corefcn/dlmread.cc,
libinterp/corefcn/dot.cc, libinterp/corefcn/dynamic-ld.cc,
libinterp/corefcn/dynamic-ld.h, libinterp/corefcn/eig.cc,
libinterp/corefcn/ellipj.cc, libinterp/corefcn/error.cc,
libinterp/corefcn/error.h, libinterp/corefcn/event-queue.h,
libinterp/corefcn/fft.cc, libinterp/corefcn/fft2.cc, libinterp/corefcn/fftn.cc,
libinterp/corefcn/file-io.cc, libinterp/corefcn/filter.cc,
libinterp/corefcn/find.cc, libinterp/corefcn/gammainc.cc,
libinterp/corefcn/gcd.cc, libinterp/corefcn/getgrent.cc,
libinterp/corefcn/getpwent.cc, libinterp/corefcn/getrusage.cc,
libinterp/corefcn/givens.cc, libinterp/corefcn/gl-render.cc,
libinterp/corefcn/gl2ps-renderer.cc, libinterp/corefcn/gl2ps-renderer.h,
libinterp/corefcn/graphics.cc, libinterp/corefcn/graphics.in.h,
libinterp/corefcn/gripes.cc, libinterp/corefcn/gripes.h,
libinterp/corefcn/help.cc, libinterp/corefcn/hess.cc,
libinterp/corefcn/hex2num.cc, libinterp/corefcn/input.cc,
libinterp/corefcn/input.h, libinterp/corefcn/inv.cc,
libinterp/corefcn/jit-ir.h, libinterp/corefcn/jit-typeinfo.cc,
libinterp/corefcn/jit-typeinfo.h, libinterp/corefcn/jit-util.h,
libinterp/corefcn/kron.cc, libinterp/corefcn/load-path.cc,
libinterp/corefcn/load-path.h, libinterp/corefcn/load-save.cc,
libinterp/corefcn/load-save.h, libinterp/corefcn/lookup.cc,
libinterp/corefcn/ls-ascii-helper.cc, libinterp/corefcn/ls-hdf5.cc,
libinterp/corefcn/ls-hdf5.h, libinterp/corefcn/ls-mat-ascii.cc,
libinterp/corefcn/ls-mat-ascii.h, libinterp/corefcn/ls-mat4.cc,
libinterp/corefcn/ls-mat5.cc, libinterp/corefcn/ls-mat5.h,
libinterp/corefcn/ls-oct-ascii.cc, libinterp/corefcn/lsode.cc,
libinterp/corefcn/lu.cc, libinterp/corefcn/luinc.cc,
libinterp/corefcn/mappers.cc, libinterp/corefcn/matrix_type.cc,
libinterp/corefcn/max.cc, libinterp/corefcn/md5sum.cc,
libinterp/corefcn/mex.cc, libinterp/corefcn/mexproto.h,
libinterp/corefcn/mgorth.cc, libinterp/corefcn/mxarray.in.h,
libinterp/corefcn/nproc.cc, libinterp/corefcn/oct-hist.cc,
libinterp/corefcn/oct-lvalue.h, libinterp/corefcn/oct-map.cc,
libinterp/corefcn/oct-map.h, libinterp/corefcn/oct-obj.h,
libinterp/corefcn/oct-prcstrm.h, libinterp/corefcn/oct-stdstrm.h,
libinterp/corefcn/oct-stream.cc, libinterp/corefcn/oct-stream.h,
libinterp/corefcn/octave-link.cc, libinterp/corefcn/octave-link.h,
libinterp/corefcn/pager.cc, libinterp/corefcn/pinv.cc,
libinterp/corefcn/pr-output.cc, libinterp/corefcn/procstream.h,
libinterp/corefcn/profiler.cc, libinterp/corefcn/pt-jit.cc,
libinterp/corefcn/pt-jit.h, libinterp/corefcn/quad.cc,
libinterp/corefcn/quadcc.cc, libinterp/corefcn/qz.cc,
libinterp/corefcn/rand.cc, libinterp/corefcn/rcond.cc,
libinterp/corefcn/regexp.cc, libinterp/corefcn/schur.cc,
libinterp/corefcn/sighandlers.cc, libinterp/corefcn/sighandlers.h,
libinterp/corefcn/sparse-xdiv.cc, libinterp/corefcn/sparse-xdiv.h,
libinterp/corefcn/sparse-xpow.cc, libinterp/corefcn/sparse.cc,
libinterp/corefcn/spparms.cc, libinterp/corefcn/sqrtm.cc,
libinterp/corefcn/str2double.cc, libinterp/corefcn/strfind.cc,
libinterp/corefcn/strfns.cc, libinterp/corefcn/sub2ind.cc,
libinterp/corefcn/svd.cc, libinterp/corefcn/syl.cc,
libinterp/corefcn/symtab.cc, libinterp/corefcn/symtab.h,
libinterp/corefcn/syscalls.cc, libinterp/corefcn/sysdep.cc,
libinterp/corefcn/sysdep.h, libinterp/corefcn/time.cc,
libinterp/corefcn/toplev.cc, libinterp/corefcn/toplev.h,
libinterp/corefcn/tril.cc, libinterp/corefcn/txt-eng-ft.cc,
libinterp/corefcn/txt-eng-ft.h, libinterp/corefcn/txt-eng.h,
libinterp/corefcn/typecast.cc, libinterp/corefcn/urlwrite.cc,
libinterp/corefcn/utils.cc, libinterp/corefcn/variables.cc,
libinterp/corefcn/variables.h, libinterp/corefcn/xdiv.cc,
libinterp/corefcn/xdiv.h, libinterp/corefcn/xnorm.h, libinterp/corefcn/xpow.cc,
libinterp/corefcn/xpow.h, libinterp/corefcn/zfstream.cc,
libinterp/corefcn/zfstream.h, libinterp/dldfcn/__delaunayn__.cc,
libinterp/dldfcn/__dsearchn__.cc, libinterp/dldfcn/__eigs__.cc,
libinterp/dldfcn/__fltk_uigetfile__.cc, libinterp/dldfcn/__glpk__.cc,
libinterp/dldfcn/__init_fltk__.cc, libinterp/dldfcn/__init_gnuplot__.cc,
libinterp/dldfcn/__magick_read__.cc, libinterp/dldfcn/__voronoi__.cc,
libinterp/dldfcn/amd.cc, libinterp/dldfcn/ccolamd.cc, libinterp/dldfcn/chol.cc,
libinterp/dldfcn/colamd.cc, libinterp/dldfcn/convhulln.cc,
libinterp/dldfcn/dmperm.cc, libinterp/dldfcn/fftw.cc, libinterp/dldfcn/qr.cc,
libinterp/dldfcn/symbfact.cc, libinterp/dldfcn/symrcm.cc,
libinterp/dldfcn/tsearch.cc, libinterp/octave-value/ov-base-diag.cc,
libinterp/octave-value/ov-base-diag.h, libinterp/octave-value/ov-base-int.cc,
libinterp/octave-value/ov-base-int.h, libinterp/octave-value/ov-base-mat.h,
libinterp/octave-value/ov-base-scalar.cc,
libinterp/octave-value/ov-base-scalar.h,
libinterp/octave-value/ov-base-sparse.cc,
libinterp/octave-value/ov-base-sparse.h, libinterp/octave-value/ov-base.cc,
libinterp/octave-value/ov-base.h, libinterp/octave-value/ov-bool-mat.cc,
libinterp/octave-value/ov-bool-mat.h, libinterp/octave-value/ov-bool-sparse.cc,
libinterp/octave-value/ov-bool-sparse.h, libinterp/octave-value/ov-bool.cc,
libinterp/octave-value/ov-bool.h, libinterp/octave-value/ov-builtin.cc,
libinterp/octave-value/ov-builtin.h, libinterp/octave-value/ov-cell.cc,
libinterp/octave-value/ov-cell.h, libinterp/octave-value/ov-ch-mat.cc,
libinterp/octave-value/ov-ch-mat.h, libinterp/octave-value/ov-class.cc,
libinterp/octave-value/ov-class.h, libinterp/octave-value/ov-colon.h,
libinterp/octave-value/ov-complex.cc, libinterp/octave-value/ov-complex.h,
libinterp/octave-value/ov-cx-diag.cc, libinterp/octave-value/ov-cx-diag.h,
libinterp/octave-value/ov-cx-mat.cc, libinterp/octave-value/ov-cx-mat.h,
libinterp/octave-value/ov-cx-sparse.cc, libinterp/octave-value/ov-cx-sparse.h,
libinterp/octave-value/ov-dld-fcn.h, libinterp/octave-value/ov-fcn-handle.cc,
libinterp/octave-value/ov-fcn-handle.h,
libinterp/octave-value/ov-fcn-inline.cc,
libinterp/octave-value/ov-fcn-inline.h, libinterp/octave-value/ov-fcn.h,
libinterp/octave-value/ov-float.cc, libinterp/octave-value/ov-float.h,
libinterp/octave-value/ov-flt-complex.cc,
libinterp/octave-value/ov-flt-complex.h,
libinterp/octave-value/ov-flt-cx-diag.cc,
libinterp/octave-value/ov-flt-cx-diag.h,
libinterp/octave-value/ov-flt-cx-mat.cc,
libinterp/octave-value/ov-flt-cx-mat.h,
libinterp/octave-value/ov-flt-re-diag.cc,
libinterp/octave-value/ov-flt-re-diag.h,
libinterp/octave-value/ov-flt-re-mat.cc,
libinterp/octave-value/ov-flt-re-mat.h, libinterp/octave-value/ov-int16.cc,
libinterp/octave-value/ov-int32.cc, libinterp/octave-value/ov-int64.cc,
libinterp/octave-value/ov-int8.cc, libinterp/octave-value/ov-intx.h,
libinterp/octave-value/ov-java.cc, libinterp/octave-value/ov-lazy-idx.h,
libinterp/octave-value/ov-mex-fcn.cc, libinterp/octave-value/ov-mex-fcn.h,
libinterp/octave-value/ov-null-mat.cc, libinterp/octave-value/ov-null-mat.h,
libinterp/octave-value/ov-oncleanup.cc, libinterp/octave-value/ov-perm.cc,
libinterp/octave-value/ov-perm.h, libinterp/octave-value/ov-range.cc,
libinterp/octave-value/ov-range.h, libinterp/octave-value/ov-re-diag.cc,
libinterp/octave-value/ov-re-diag.h, libinterp/octave-value/ov-re-mat.cc,
libinterp/octave-value/ov-re-mat.h, libinterp/octave-value/ov-re-sparse.cc,
libinterp/octave-value/ov-re-sparse.h, libinterp/octave-value/ov-scalar.cc,
libinterp/octave-value/ov-scalar.h, libinterp/octave-value/ov-str-mat.cc,
libinterp/octave-value/ov-str-mat.h, libinterp/octave-value/ov-struct.cc,
libinterp/octave-value/ov-struct.h, libinterp/octave-value/ov-type-conv.h,
libinterp/octave-value/ov-typeinfo.cc, libinterp/octave-value/ov-typeinfo.h,
libinterp/octave-value/ov-uint16.cc, libinterp/octave-value/ov-uint32.cc,
libinterp/octave-value/ov-uint64.cc, libinterp/octave-value/ov-uint8.cc,
libinterp/octave-value/ov-usr-fcn.cc, libinterp/octave-value/ov-usr-fcn.h,
libinterp/octave-value/ov.cc, libinterp/octave-value/ov.h, libinterp/octave.cc,
libinterp/operators/op-b-bm.cc, libinterp/operators/op-b-sbm.cc,
libinterp/operators/op-bm-b.cc, libinterp/operators/op-bm-bm.cc,
libinterp/operators/op-cdm-cdm.cc, libinterp/operators/op-chm.cc,
libinterp/operators/op-class.cc, libinterp/operators/op-cm-cm.cc,
libinterp/operators/op-cm-cs.cc, libinterp/operators/op-cm-s.cc,
libinterp/operators/op-cm-scm.cc, libinterp/operators/op-cm-sm.cc,
libinterp/operators/op-cs-cm.cc, libinterp/operators/op-cs-cs.cc,
libinterp/operators/op-cs-scm.cc, libinterp/operators/op-cs-sm.cc,
libinterp/operators/op-dm-dm.cc, libinterp/operators/op-dm-scm.cc,
libinterp/operators/op-double-conv.cc, libinterp/operators/op-fcdm-fcdm.cc,
libinterp/operators/op-fcm-fcm.cc, libinterp/operators/op-fcm-fcs.cc,
libinterp/operators/op-fcm-fm.cc, libinterp/operators/op-fcm-fs.cc,
libinterp/operators/op-fcs-fcm.cc, libinterp/operators/op-fcs-fcs.cc,
libinterp/operators/op-fcs-fm.cc, libinterp/operators/op-fcs-fs.cc,
libinterp/operators/op-fdm-fdm.cc, libinterp/operators/op-float-conv.cc,
libinterp/operators/op-fm-fcm.cc, libinterp/operators/op-fm-fcs.cc,
libinterp/operators/op-fm-fm.cc, libinterp/operators/op-fm-fs.cc,
libinterp/operators/op-fs-fcm.cc, libinterp/operators/op-fs-fcs.cc,
libinterp/operators/op-fs-fm.cc, libinterp/operators/op-fs-fs.cc,
libinterp/operators/op-m-cm.cc, libinterp/operators/op-m-cs.cc,
libinterp/operators/op-m-m.cc, libinterp/operators/op-m-s.cc,
libinterp/operators/op-m-scm.cc, libinterp/operators/op-m-sm.cc,
libinterp/operators/op-pm-scm.cc, libinterp/operators/op-range.cc,
libinterp/operators/op-s-cm.cc, libinterp/operators/op-s-cs.cc,
libinterp/operators/op-s-scm.cc, libinterp/operators/op-sbm-b.cc,
libinterp/operators/op-sbm-bm.cc, libinterp/operators/op-sbm-sbm.cc,
libinterp/operators/op-scm-cm.cc, libinterp/operators/op-scm-cs.cc,
libinterp/operators/op-scm-m.cc, libinterp/operators/op-scm-s.cc,
libinterp/operators/op-scm-scm.cc, libinterp/operators/op-scm-sm.cc,
libinterp/operators/op-sm-cm.cc, libinterp/operators/op-sm-m.cc,
libinterp/operators/op-sm-s.cc, libinterp/operators/op-sm-scm.cc,
libinterp/operators/op-sm-sm.cc, libinterp/operators/op-str-m.cc,
libinterp/operators/op-str-s.cc, libinterp/operators/op-str-str.cc,
libinterp/operators/ops.h, libinterp/parse-tree/lex.h,
libinterp/parse-tree/parse.h, libinterp/parse-tree/pt-arg-list.cc,
libinterp/parse-tree/pt-arg-list.h, libinterp/parse-tree/pt-assign.cc,
libinterp/parse-tree/pt-assign.h, libinterp/parse-tree/pt-binop.cc,
libinterp/parse-tree/pt-binop.h, libinterp/parse-tree/pt-bp.h,
libinterp/parse-tree/pt-cbinop.cc, libinterp/parse-tree/pt-check.cc,
libinterp/parse-tree/pt-colon.cc, libinterp/parse-tree/pt-colon.h,
libinterp/parse-tree/pt-const.cc, libinterp/parse-tree/pt-decl.cc,
libinterp/parse-tree/pt-decl.h, libinterp/parse-tree/pt-eval.cc,
libinterp/parse-tree/pt-except.h, libinterp/parse-tree/pt-exp.h,
libinterp/parse-tree/pt-fcn-handle.cc, libinterp/parse-tree/pt-id.cc,
libinterp/parse-tree/pt-id.h, libinterp/parse-tree/pt-idx.cc,
libinterp/parse-tree/pt-idx.h, libinterp/parse-tree/pt-loop.h,
libinterp/parse-tree/pt-mat.cc, libinterp/parse-tree/pt-misc.cc,
libinterp/parse-tree/pt-misc.h, libinterp/parse-tree/pt-pr-code.cc,
libinterp/parse-tree/pt-select.h, libinterp/parse-tree/pt-stmt.h,
libinterp/parse-tree/token.h, libinterp/version.cc:
Use GNU style coding conventions for code in libinterp/
author | Rik <rik@octave.org> |
---|---|
date | Mon, 28 Oct 2013 19:51:46 -0700 |
parents | d63878346099 |
children | 9ac2357f19bc |
line wrap: on
line source
/* Copyright (C) 1996-2013 John W. Eaton This file is part of Octave. Octave is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. Octave is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with Octave; see the file COPYING. If not, see <http://www.gnu.org/licenses/>. */ // Based on Tony Richardson's filter.m. // // Originally translated to C++ by KH (Kurt.Hornik@wu-wien.ac.at) // with help from Fritz Leisch and Andreas Weingessel on Oct 20, 1994. // // Rewritten to use templates to handle both real and complex cases by // jwe, Wed Nov 1 19:15:29 1995. #ifdef HAVE_CONFIG_H #include <config.h> #endif #include "quit.h" #include "defun.h" #include "error.h" #include "oct-obj.h" #if !defined (CXX_NEW_FRIEND_TEMPLATE_DECL) extern MArray<double> filter (MArray<double>&, MArray<double>&, MArray<double>&, int dim); extern MArray<Complex> filter (MArray<Complex>&, MArray<Complex>&, MArray<Complex>&, int dim); extern MArray<float> filter (MArray<float>&, MArray<float>&, MArray<float>&, int dim); extern MArray<FloatComplex> filter (MArray<FloatComplex>&, MArray<FloatComplex>&, MArray<FloatComplex>&, int dim); #endif template <class T> MArray<T> filter (MArray<T>& b, MArray<T>& a, MArray<T>& x, MArray<T>& si, int dim = 0) { MArray<T> y; octave_idx_type a_len = a.length (); octave_idx_type b_len = b.length (); octave_idx_type ab_len = a_len > b_len ? a_len : b_len; // FIXME: The two lines below should be unecessary because // this template is called with a and b as column vectors // already. However the a.resize line is currently (2011/04/26) // necessary to stop bug #33164. b.resize (dim_vector (ab_len, 1), 0.0); if (a_len > 1) a.resize (dim_vector (ab_len, 1), 0.0); T norm = a (0); if (norm == static_cast<T>(0.0)) { error ("filter: the first element of A must be non-zero"); return y; } dim_vector x_dims = x.dims (); if (dim < 0 || dim > x_dims.length ()) { error ("filter: DIM must be a valid dimension"); return y; } octave_idx_type x_len = x_dims(dim); dim_vector si_dims = si.dims (); octave_idx_type si_len = si_dims(0); if (si_len != ab_len - 1) { error ("filter: first dimension of SI must be of length max (length (a), length (b)) - 1"); return y; } if (si_dims.length () != x_dims.length ()) { error ("filter: dimensionality of SI and X must agree"); return y; } for (octave_idx_type i = 1; i < dim; i++) { if (si_dims(i) != x_dims(i-1)) { error ("filter: dimensionality of SI and X must agree"); return y; } } for (octave_idx_type i = dim+1; i < x_dims.length (); i++) { if (si_dims(i) != x_dims(i)) { error ("filter: dimensionality of SI and X must agree"); return y; } } if (x_len == 0) return x; if (norm != static_cast<T>(1.0)) { a = a / norm; b = b / norm; } if (a_len <= 1 && si_len <= 0) return b(0) * x; y.resize (x_dims, 0.0); int x_stride = 1; for (int i = 0; i < dim; i++) x_stride *= x_dims(i); octave_idx_type x_num = x_dims.numel () / x_len; for (octave_idx_type num = 0; num < x_num; num++) { octave_idx_type x_offset; if (x_stride == 1) x_offset = num * x_len; else { octave_idx_type x_offset2 = 0; x_offset = num; while (x_offset >= x_stride) { x_offset -= x_stride; x_offset2++; } x_offset += x_offset2 * x_stride * x_len; } octave_idx_type si_offset = num * si_len; if (a_len > 1) { T *py = y.fortran_vec (); T *psi = si.fortran_vec (); const T *pa = a.data (); const T *pb = b.data (); const T *px = x.data (); psi += si_offset; for (octave_idx_type i = 0, idx = x_offset; i < x_len; i++, idx += x_stride) { py[idx] = psi[0] + pb[0] * px[idx]; if (si_len > 0) { for (octave_idx_type j = 0; j < si_len - 1; j++) { OCTAVE_QUIT; psi[j] = psi[j+1] - pa[j+1] * py[idx] + pb[j+1] * px[idx]; } psi[si_len-1] = pb[si_len] * px[idx] - pa[si_len] * py[idx]; } else { OCTAVE_QUIT; psi[0] = pb[si_len] * px[idx] - pa[si_len] * py[idx]; } } } else if (si_len > 0) { T *py = y.fortran_vec (); T *psi = si.fortran_vec (); const T *pb = b.data (); const T *px = x.data (); psi += si_offset; for (octave_idx_type i = 0, idx = x_offset; i < x_len; i++, idx += x_stride) { py[idx] = psi[0] + pb[0] * px[idx]; if (si_len > 1) { for (octave_idx_type j = 0; j < si_len - 1; j++) { OCTAVE_QUIT; psi[j] = psi[j+1] + pb[j+1] * px[idx]; } psi[si_len-1] = pb[si_len] * px[idx]; } else { OCTAVE_QUIT; psi[0] = pb[1] * px[idx]; } } } } return y; } #if !defined (CXX_NEW_FRIEND_TEMPLATE_DECL) extern MArray<double> filter (MArray<double>&, MArray<double>&, MArray<double>&, MArray<double>&, int dim); extern MArray<Complex> filter (MArray<Complex>&, MArray<Complex>&, MArray<Complex>&, MArray<Complex>&, int dim); extern MArray<float> filter (MArray<float>&, MArray<float>&, MArray<float>&, MArray<float>&, int dim); extern MArray<FloatComplex> filter (MArray<FloatComplex>&, MArray<FloatComplex>&, MArray<FloatComplex>&, MArray<FloatComplex>&, int dim); #endif template <class T> MArray<T> filter (MArray<T>& b, MArray<T>& a, MArray<T>& x, int dim = -1) { dim_vector x_dims = x.dims (); if (dim < 0) { // Find first non-singleton dimension while (dim < x_dims.length () && x_dims(dim) <= 1) dim++; // All dimensions singleton, pick first dimension if (dim == x_dims.length ()) dim = 0; } else if (dim < 0 || dim > x_dims.length ()) { error ("filter: DIM must be a valid dimension"); return MArray<T> (); } octave_idx_type a_len = a.length (); octave_idx_type b_len = b.length (); octave_idx_type si_len = (a_len > b_len ? a_len : b_len) - 1; dim_vector si_dims = x.dims (); for (int i = dim; i > 0; i--) si_dims(i) = si_dims(i-1); si_dims(0) = si_len; MArray<T> si (si_dims, T (0.0)); return filter (b, a, x, si, dim); } DEFUN (filter, args, nargout, "-*- texinfo -*-\n\ @deftypefn {Built-in Function} {y =} filter (@var{b}, @var{a}, @var{x})\n\ @deftypefnx {Built-in Function} {[@var{y}, @var{sf}] =} filter (@var{b}, @var{a}, @var{x}, @var{si})\n\ @deftypefnx {Built-in Function} {[@var{y}, @var{sf}] =} filter (@var{b}, @var{a}, @var{x}, [], @var{dim})\n\ @deftypefnx {Built-in Function} {[@var{y}, @var{sf}] =} filter (@var{b}, @var{a}, @var{x}, @var{si}, @var{dim})\n\ Return the solution to the following linear, time-invariant difference\n\ equation:\n\ @tex\n\ $$\n\ \\sum_{k=0}^N a_{k+1} y_{n-k} = \\sum_{k=0}^M b_{k+1} x_{n-k}, \\qquad\n\ 1 \\le n \\le P\n\ $$\n\ @end tex\n\ @ifnottex\n\ @c Set example in small font to prevent overfull line\n\ \n\ @smallexample\n\ @group\n\ N M\n\ SUM a(k+1) y(n-k) = SUM b(k+1) x(n-k) for 1<=n<=length(x)\n\ k=0 k=0\n\ @end group\n\ @end smallexample\n\ \n\ @end ifnottex\n\ \n\ @noindent\n\ where\n\ @ifnottex\n\ N=length(a)-1 and M=length(b)-1.\n\ @end ifnottex\n\ @tex\n\ $a \\in \\Re^{N-1}$, $b \\in \\Re^{M-1}$, and $x \\in \\Re^P$.\n\ @end tex\n\ The result is calculated over the first non-singleton dimension of @var{x}\n\ or over @var{dim} if supplied.\n\ \n\ An equivalent form of the equation is:\n\ @tex\n\ $$\n\ y_n = -\\sum_{k=1}^N c_{k+1} y_{n-k} + \\sum_{k=0}^M d_{k+1} x_{n-k}, \\qquad\n\ 1 \\le n \\le P\n\ $$\n\ @end tex\n\ @ifnottex\n\ @c Set example in small font to prevent overfull line\n\ \n\ @smallexample\n\ @group\n\ N M\n\ y(n) = - SUM c(k+1) y(n-k) + SUM d(k+1) x(n-k) for 1<=n<=length(x)\n\ k=1 k=0\n\ @end group\n\ @end smallexample\n\ \n\ @end ifnottex\n\ \n\ @noindent\n\ where\n\ @ifnottex\n\ c = a/a(1) and d = b/a(1).\n\ @end ifnottex\n\ @tex\n\ $c = a/a_1$ and $d = b/a_1$.\n\ @end tex\n\ \n\ If the fourth argument @var{si} is provided, it is taken as the\n\ initial state of the system and the final state is returned as\n\ @var{sf}. The state vector is a column vector whose length is\n\ equal to the length of the longest coefficient vector minus one.\n\ If @var{si} is not supplied, the initial state vector is set to all\n\ zeros.\n\ \n\ In terms of the Z Transform, y is the result of passing the discrete-\n\ time signal x through a system characterized by the following rational\n\ system function:\n\ @tex\n\ $$\n\ H(z) = {\\displaystyle\\sum_{k=0}^M d_{k+1} z^{-k}\n\ \\over 1 + \\displaystyle\\sum_{k+1}^N c_{k+1} z^{-k}}\n\ $$\n\ @end tex\n\ @ifnottex\n\ \n\ @example\n\ @group\n\ M\n\ SUM d(k+1) z^(-k)\n\ k=0\n\ H(z) = ---------------------\n\ N\n\ 1 + SUM c(k+1) z^(-k)\n\ k=1\n\ @end group\n\ @end example\n\ \n\ @end ifnottex\n\ @seealso{filter2, fftfilt, freqz}\n\ @end deftypefn") { octave_value_list retval; int nargin = args.length (); if (nargin < 3 || nargin > 5) { print_usage (); return retval; } const char *errmsg = "filter: arguments a and b must be vectors"; int dim; dim_vector x_dims = args(2).dims (); if (nargin == 5) { dim = args(4).nint_value () - 1; if (dim < 0 || dim >= x_dims.length ()) { error ("filter: DIM must be a valid dimension"); return retval; } } else { // Find first non-singleton dimension dim = 0; while (dim < x_dims.length () && x_dims(dim) <= 1) dim++; // All dimensions singleton, pick first dimension if (dim == x_dims.length ()) dim = 0; } bool isfloat = (args(0).is_single_type () || args(1).is_single_type () || args(2).is_single_type () || (nargin >= 4 && args(3).is_single_type ())); if (args(0).is_complex_type () || args(1).is_complex_type () || args(2).is_complex_type () || (nargin >= 4 && args(3).is_complex_type ())) { if (isfloat) { FloatComplexColumnVector b (args(0).float_complex_vector_value ()); FloatComplexColumnVector a (args(1).float_complex_vector_value ()); FloatComplexNDArray x (args(2).float_complex_array_value ()); if (! error_state) { FloatComplexNDArray si; if (nargin == 3 || args(3).is_empty ()) { octave_idx_type a_len = a.length (); octave_idx_type b_len = b.length (); octave_idx_type si_len = (a_len > b_len ? a_len : b_len) - 1; dim_vector si_dims = x.dims (); for (int i = dim; i > 0; i--) si_dims(i) = si_dims(i-1); si_dims(0) = si_len; si.resize (si_dims, 0.0); } else { si = args(3).float_complex_array_value (); if (si.is_vector () && x.is_vector ()) si = si.reshape (dim_vector (si.numel (), 1)); } if (! error_state) { FloatComplexNDArray y (filter (b, a, x, si, dim)); if (nargout == 2) retval(1) = si; retval(0) = y; } else error (errmsg); } else error (errmsg); } else { ComplexColumnVector b (args(0).complex_vector_value ()); ComplexColumnVector a (args(1).complex_vector_value ()); ComplexNDArray x (args(2).complex_array_value ()); if (! error_state) { ComplexNDArray si; if (nargin == 3 || args(3).is_empty ()) { octave_idx_type a_len = a.length (); octave_idx_type b_len = b.length (); octave_idx_type si_len = (a_len > b_len ? a_len : b_len) - 1; dim_vector si_dims = x.dims (); for (int i = dim; i > 0; i--) si_dims(i) = si_dims(i-1); si_dims(0) = si_len; si.resize (si_dims, 0.0); } else { si = args(3).complex_array_value (); if (si.is_vector () && x.is_vector ()) si = si.reshape (dim_vector (si.numel (), 1)); } if (! error_state) { ComplexNDArray y (filter (b, a, x, si, dim)); if (nargout == 2) retval(1) = si; retval(0) = y; } else error (errmsg); } else error (errmsg); } } else { if (isfloat) { FloatColumnVector b (args(0).float_vector_value ()); FloatColumnVector a (args(1).float_vector_value ()); FloatNDArray x (args(2).float_array_value ()); if (! error_state) { FloatNDArray si; if (nargin == 3 || args(3).is_empty ()) { octave_idx_type a_len = a.length (); octave_idx_type b_len = b.length (); octave_idx_type si_len = (a_len > b_len ? a_len : b_len) - 1; dim_vector si_dims = x.dims (); for (int i = dim; i > 0; i--) si_dims(i) = si_dims(i-1); si_dims(0) = si_len; si.resize (si_dims, 0.0); } else { si = args(3).float_array_value (); if (si.is_vector () && x.is_vector ()) si = si.reshape (dim_vector (si.numel (), 1)); } if (! error_state) { FloatNDArray y (filter (b, a, x, si, dim)); if (nargout == 2) retval(1) = si; retval(0) = y; } else error (errmsg); } else error (errmsg); } else { ColumnVector b (args(0).vector_value ()); ColumnVector a (args(1).vector_value ()); NDArray x (args(2).array_value ()); if (! error_state) { NDArray si; if (nargin == 3 || args(3).is_empty ()) { octave_idx_type a_len = a.length (); octave_idx_type b_len = b.length (); octave_idx_type si_len = (a_len > b_len ? a_len : b_len) - 1; dim_vector si_dims = x.dims (); for (int i = dim; i > 0; i--) si_dims(i) = si_dims(i-1); si_dims(0) = si_len; si.resize (si_dims, 0.0); } else { si = args(3).array_value (); if (si.is_vector () && x.is_vector ()) si = si.reshape (dim_vector (si.numel (), 1)); } if (! error_state) { NDArray y (filter (b, a, x, si, dim)); if (nargout == 2) retval(1) = si; retval(0) = y; } else error (errmsg); } else error (errmsg); } } return retval; } template MArray<double> filter (MArray<double>&, MArray<double>&, MArray<double>&, MArray<double>&, int dim); template MArray<double> filter (MArray<double>&, MArray<double>&, MArray<double>&, int dim); template MArray<Complex> filter (MArray<Complex>&, MArray<Complex>&, MArray<Complex>&, MArray<Complex>&, int dim); template MArray<Complex> filter (MArray<Complex>&, MArray<Complex>&, MArray<Complex>&, int dim); template MArray<float> filter (MArray<float>&, MArray<float>&, MArray<float>&, MArray<float>&, int dim); template MArray<float> filter (MArray<float>&, MArray<float>&, MArray<float>&, int dim); template MArray<FloatComplex> filter (MArray<FloatComplex>&, MArray<FloatComplex>&, MArray<FloatComplex>&, MArray<FloatComplex>&, int dim); template MArray<FloatComplex> filter (MArray<FloatComplex>&, MArray<FloatComplex>&, MArray<FloatComplex>&, int dim); /* %!shared a, b, x, r %!test %! a = [1 1]; %! b = [1 1]; %! x = zeros (1,10); x(1) = 1; %! assert (filter (b, [1], x ), [1 1 0 0 0 0 0 0 0 0]); %! assert (filter (b, [1], x.'), [1 1 0 0 0 0 0 0 0 0].'); %! assert (filter (b.', [1], x ), [1 1 0 0 0 0 0 0 0 0] ); %! assert (filter (b.', [1], x.'), [1 1 0 0 0 0 0 0 0 0].'); %! assert (filter ([1], a, x ), [+1 -1 +1 -1 +1 -1 +1 -1 +1 -1] ); %! assert (filter ([1], a, x.'), [+1 -1 +1 -1 +1 -1 +1 -1 +1 -1].'); %! assert (filter ([1], a.', x ), [+1 -1 +1 -1 +1 -1 +1 -1 +1 -1] ); %! assert (filter ([1], a.', x.'), [+1 -1 +1 -1 +1 -1 +1 -1 +1 -1].'); %! assert (filter (b, a, x ), [1 0 0 0 0 0 0 0 0 0] ); %! assert (filter (b.', a, x ), [1 0 0 0 0 0 0 0 0 0] ); %! assert (filter (b, a.', x ), [1 0 0 0 0 0 0 0 0 0] ); %! assert (filter (b.', a, x ), [1 0 0 0 0 0 0 0 0 0] ); %! assert (filter (b, a, x.'), [1 0 0 0 0 0 0 0 0 0].'); %! assert (filter (b.', a, x.'), [1 0 0 0 0 0 0 0 0 0].'); %! assert (filter (b, a.', x.'), [1 0 0 0 0 0 0 0 0 0].'); %! assert (filter (b.', a, x.'), [1 0 0 0 0 0 0 0 0 0].'); %!test %! r = sqrt (1/2) * (1+i); %! a = a*r; %! b = b*r; %! assert (filter (b, [1], x ), r*[1 1 0 0 0 0 0 0 0 0] ); %! assert (filter (b, [1], r*x ), r*r*[1 1 0 0 0 0 0 0 0 0] ); %! assert (filter (b, [1], x.' ), r*[1 1 0 0 0 0 0 0 0 0].' ); %! assert (filter (b, a, x ), [1 0 0 0 0 0 0 0 0 0] ); %! assert (filter (b, a, r*x ), r*[1 0 0 0 0 0 0 0 0 0] ); %!shared a, b, x, y, so %!test %! a = [1,1]; %! b = [1,1]; %! x = zeros (1,10); x(1) = 1; %! [y, so] = filter (b, [1], x, [-1]); %! assert (y, [0 1 0 0 0 0 0 0 0 0]); %! assert (so, 0); %!test %! x = zeros (10,3); x(1,1) = -1; x(1,2) = 1; %! y0 = zeros (10,3); y0(1:2,1) = -1; y0(1:2,2) = 1; %! y = filter (b, [1], x); %! assert (y, y0); %!test %! a = [1,1]; %! b=[1,1]; %! x = zeros (4,4,2); x(1,1:4,1) = +1; x(1,1:4,2) = -1; %! y0 = zeros (4,4,2); y0(1:2,1:4,1) = +1; y0(1:2,1:4,2) = -1; %! y = filter (b, [1], x); %! assert (y, y0); %!assert (filter (1, ones (10,1) / 10, []), []) %!assert (filter (1, ones (10,1) / 10, zeros (0,10)), zeros (0,10)) %!assert (filter (1, ones (10,1) / 10, single (1:5)), repmat (single (10), 1, 5)) %% Test using initial conditions %!assert (filter ([1, 1, 1], [1, 1], [1 2], [1, 1]), [2 2]) %!assert (filter ([1, 1, 1], [1, 1], [1 2], [1, 1]'), [2 2]) %!assert (filter ([1, 3], [1], [1 2; 3 4; 5 6], [4, 5]), [5 7; 6 10; 14 18]) %!error (filter ([1, 3], [1], [1 2; 3 4; 5 6], [4, 5]')) %!assert (filter ([1, 3, 2], [1], [1 2; 3 4; 5 6], [1 0 0; 1 0 0], 2), [2 6; 3 13; 5 21]) ## Test of DIM parameter %!test %! x = ones (2, 1, 3, 4); %! x(1,1,:,:) = [1 2 3 4; 5 6 7 8; 9 10 11 12]; %! y0 = [1 1 6 2 15 3 2 1 8 2 18 3 3 1 10 2 21 3 4 1 12 2 24 3]; %! y0 = reshape (y0, size (x)); %! y = filter ([1 1 1], 1, x, [], 3); %! assert (y, y0); */