Mercurial > octave-libtiff
view scripts/general/logspace.m @ 2311:2b5788792cad
[project @ 1996-07-11 20:18:38 by jwe]
author | jwe |
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date | Thu, 11 Jul 1996 20:18:38 +0000 |
parents | 5cffc4b8de57 |
children | 5ca126254d15 |
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### Copyright (C) 1996 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 2, 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, write to the Free ### Software Foundation, 59 Temple Place - Suite 330, Boston, MA ### 02111-1307, USA. ## usage: logspace (x1, x2, n) ## ## Return a vector of n logarithmically equally spaced points between ## x1 and x2 inclusive. ## ## If the final argument is omitted, n = 50 is assumed. ## ## All three arguments must be scalars. ## ## Note that if if x2 is pi, the points are between 10^x1 and pi, NOT ## 10^x1 and 10^pi. ## ## Yes, this is pretty stupid, because you could achieve the same ## result with logspace (x1, log10 (pi)), but Matlab does this, and ## claims that is useful for signal processing applications. ## ## See also: linspace function retval = logspace (x1, x2, n) if (nargin == 2) npoints = 50; elseif (nargin == 3) if (length (n) == 1) npoints = fix (n); else error ("logspace: arguments must be scalars"); endif else usage ("logspace (x1, x2 [, n])"); endif if (npoints < 2) error ("logspace: npoints must be greater than 2"); endif if (length (x1) == 1 && length (x2) == 1) x2_tmp = x2; if (x2 == pi) x2_tmp = log10 (pi); endif retval = 10 .^ (linspace (x1, x2_tmp, npoints)); else error ("logspace: arguments must be scalars"); endif endfunction