Mercurial > hg > octave-nkf
annotate scripts/plot/contourc.m @ 8790:a013ff655ca4
Trivial changes to demos to produce a more pleasant output for octave+gnuplot+aquaterm.
| author | Ben Abbott <bpabbott@mac.com> |
|---|---|
| date | Wed, 18 Feb 2009 00:46:24 -0500 |
| parents | b93ac0586e4b |
| children | eb63fbe60fab |
| rev | line source |
|---|---|
| 7017 | 1 ## Copyright (C) 2003, 2007 Shai Ayal |
| 6257 | 2 ## |
| 6440 | 3 ## This file is part of Octave. |
| 4 ## | |
| 5 ## Octave is free software; you can redistribute it and/or modify it | |
| 6257 | 6 ## under the terms of the GNU General Public License as published by |
| 7016 | 7 ## the Free Software Foundation; either version 3 of the License, or (at |
| 8 ## your option) any later version. | |
| 6257 | 9 ## |
| 6440 | 10 ## Octave is distributed in the hope that it will be useful, but |
| 6257 | 11 ## WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 13 ## General Public License for more details. | |
| 14 ## | |
| 15 ## You should have received a copy of the GNU General Public License | |
| 7016 | 16 ## along with Octave; see the file COPYING. If not, see |
| 17 ## <http://www.gnu.org/licenses/>. | |
| 6257 | 18 |
| 19 ## -*- texinfo -*- | |
| 6590 | 20 ## @deftypefn {Function File} {[@var{c}, @var{lev}] =} contourc (@var{x}, @var{y}, @var{z}, @var{vn}) |
|
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spelling corrections
Brian Gough<bjg@network-theory.co.uk>
parents:
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21 ## Compute isolines (contour lines) of the matrix @var{z}. |
| 6257 | 22 ## Parameters @var{x}, @var{y} and @var{vn} are optional. |
| 23 ## | |
| 24 ## The return value @var{lev} is a vector of the contour levels. | |
| 25 ## The return value @var{c} is a 2 by @var{n} matrix containing the | |
| 26 ## contour lines in the following format | |
| 27 ## | |
| 28 ## @example | |
| 6547 | 29 ## @var{c} = [lev1, x1, x2, ..., levn, x1, x2, ... |
| 30 ## len1, y1, y2, ..., lenn, y1, y2, ...] | |
| 6257 | 31 ## @end example |
| 32 ## | |
| 33 ## @noindent | |
| 34 ## in which contour line @var{n} has a level (height) of @var{levn} and | |
| 35 ## length of @var{lenn}. | |
| 36 ## | |
| 37 ## If @var{x} and @var{y} are omitted they are taken as the row/column | |
| 38 ## index of @var{z}. @var{vn} is either a scalar denoting the number of lines | |
| 39 ## to compute or a vector containing the values of the lines. If only one | |
| 40 ## value is wanted, set @code{@var{vn} = [val, val]}; | |
| 41 ## If @var{vn} is omitted it defaults to 10. | |
| 42 ## | |
| 6592 | 43 ## For example, |
| 6257 | 44 ## @example |
| 6592 | 45 ## @group |
| 46 ## x = 0:2; | |
| 47 ## y = x; | |
| 48 ## z = x' * y; | |
| 49 ## contourc (x, y, z, 2:3) | |
| 50 ## @result{} 2.0000 2.0000 1.0000 3.0000 1.5000 2.0000 | |
| 51 ## 2.0000 1.0000 2.0000 2.0000 2.0000 1.5000 | |
| 52 ## | |
| 53 ## @end group | |
| 6257 | 54 ## @end example |
| 55 ## @seealso{contour} | |
| 56 ## @end deftypefn | |
| 57 | |
| 7327 | 58 ## Author: Shai Ayal <shaiay@users.sourceforge.net> |
| 6257 | 59 |
| 8236 | 60 function [cout, lev] = contourc (varargin) |
| 6257 | 61 |
| 62 if (nargin == 1) | |
| 63 vn = 10; | |
| 64 z = varargin{1}; | |
| 7327 | 65 [nr, nc] = size (z); |
| 66 x = 1:nc; | |
| 67 y = 1:nr; | |
| 6257 | 68 elseif (nargin == 2) |
| 69 vn = varargin{2}; | |
| 70 z = varargin{1}; | |
| 7327 | 71 [nr, nc] = size (z); |
| 72 x = 1:nc; | |
| 73 y = 1:nr; | |
| 6257 | 74 elseif (nargin == 3) |
| 75 vn = 10; | |
| 76 x = varargin{1}; | |
| 77 y = varargin{2}; | |
| 78 z = varargin{3}; | |
| 79 elseif (nargin == 4) | |
| 80 vn = varargin{4}; | |
| 81 x = varargin{1}; | |
| 82 y = varargin{2}; | |
| 83 z = varargin{3}; | |
| 84 else | |
| 85 print_usage (); | |
| 86 endif | |
| 87 | |
| 88 if (isscalar (vn)) | |
| 89 vv = linspace (min (z(:)), max (z(:)), vn+2)(2:end-1); | |
| 90 else | |
| 91 vv = unique (sort (vn)); | |
| 92 endif | |
| 93 | |
| 7327 | 94 if (isvector (x) && isvector (y)) |
| 95 c = __contourc__ (x(:)', y(:)', z, vv); | |
| 96 else | |
| 97 ## Indexes x,y for the purpose of __contourc__. | |
| 98 ii = 1:size (z,2); | |
| 99 jj = 1:size (z,1); | |
| 100 | |
| 101 ## Now call __contourc__ for the real work... | |
| 102 c = __contourc__ (ii, jj, z, vv); | |
| 103 | |
| 104 ## Map the contour lines from index space (i,j) back | |
| 105 ## to the original grid (x,y) | |
| 106 i = 1; | |
| 6257 | 107 |
| 7327 | 108 while (i < size (c,2)) |
| 109 clen = c(2, i); | |
| 110 ind = i + [1 : clen]; | |
| 6257 | 111 |
| 7327 | 112 ci = c(1, ind); |
| 113 cj = c(2,ind); | |
| 114 | |
| 115 ## due to rounding errors some elements of ci and cj | |
| 116 ## can fall out of the range of ii and jj and interp2 would | |
| 117 ## return NA for those values. | |
| 118 ## The permitted range is enforced here: | |
| 119 | |
| 120 ci = max (ci, 1); ci = min (ci, size (z, 2)); | |
| 121 cj = max (cj, 1); cj = min (cj, size (z, 1)); | |
| 122 | |
| 123 c(1, ind) = interp2 (ii, jj, x, ci, cj); | |
| 124 c(2, ind) = interp2 (ii, jj, y, ci, cj); | |
| 125 | |
| 126 i = i + clen + 1; | |
| 127 endwhile | |
| 6257 | 128 endif |
| 7327 | 129 |
| 8236 | 130 if (nargout > 0) |
| 131 cout = c; | |
| 6257 | 132 lev = vv; |
| 133 endif | |
| 134 | |
| 135 endfunction | |
| 7245 | 136 |
|
8790
a013ff655ca4
Trivial changes to demos to produce a more pleasant output for octave+gnuplot+aquaterm.
Ben Abbott <bpabbott@mac.com>
parents:
8325
diff
changeset
|
137 %!test |
| 7245 | 138 %! x = 0:2; |
| 139 %! y = x; | |
| 140 %! z = x' * y; | |
|
8790
a013ff655ca4
Trivial changes to demos to produce a more pleasant output for octave+gnuplot+aquaterm.
Ben Abbott <bpabbott@mac.com>
parents:
8325
diff
changeset
|
141 %! [c_actual, lev_actual]= contourc (x, y, z, 2:3); |
|
a013ff655ca4
Trivial changes to demos to produce a more pleasant output for octave+gnuplot+aquaterm.
Ben Abbott <bpabbott@mac.com>
parents:
8325
diff
changeset
|
142 %! c_expected = [2, 1, 1, 2, 2, 3, 1.5, 2; 4, 2, 2, 1, 1, 2, 2, 1.5]; |
|
a013ff655ca4
Trivial changes to demos to produce a more pleasant output for octave+gnuplot+aquaterm.
Ben Abbott <bpabbott@mac.com>
parents:
8325
diff
changeset
|
143 %! lev_expected = [2 3]; |
|
a013ff655ca4
Trivial changes to demos to produce a more pleasant output for octave+gnuplot+aquaterm.
Ben Abbott <bpabbott@mac.com>
parents:
8325
diff
changeset
|
144 %! assert (c_actual, c_expected, eps) |
|
a013ff655ca4
Trivial changes to demos to produce a more pleasant output for octave+gnuplot+aquaterm.
Ben Abbott <bpabbott@mac.com>
parents:
8325
diff
changeset
|
145 %! assert (lev_actual, lev_expected, eps) |
|
a013ff655ca4
Trivial changes to demos to produce a more pleasant output for octave+gnuplot+aquaterm.
Ben Abbott <bpabbott@mac.com>
parents:
8325
diff
changeset
|
146 |
|
a013ff655ca4
Trivial changes to demos to produce a more pleasant output for octave+gnuplot+aquaterm.
Ben Abbott <bpabbott@mac.com>
parents:
8325
diff
changeset
|
147 |