Mercurial > hg > octave-lyh
annotate scripts/statistics/base/histc.m @ 8933:346fde2030b5
scripts/statistics/base/histc.m: update copyright notice to match the rest of Octave
| author | Soren Hauberg <hauberg@gmail.com> |
|---|---|
| date | Sun, 08 Mar 2009 19:18:44 +0100 |
| parents | 2d0f8692a82e |
| children | cae073411b03 |
| rev | line source |
|---|---|
| 8932 | 1 ## Copyright (C) 2009, Søren Hauberg |
| 2 ## | |
| 3 ## This file is part of Octave. | |
| 4 ## | |
| 5 ## Octave is free software; you can redistribute it and/or modify it | |
| 6 ## under the terms of the GNU General Public License as published by | |
|
8933
346fde2030b5
scripts/statistics/base/histc.m: update copyright notice to match the rest of Octave
Soren Hauberg <hauberg@gmail.com>
parents:
8932
diff
changeset
|
7 ## the Free Software Foundation; either version 3 of the License, or (at |
|
346fde2030b5
scripts/statistics/base/histc.m: update copyright notice to match the rest of Octave
Soren Hauberg <hauberg@gmail.com>
parents:
8932
diff
changeset
|
8 ## your option) any later version. |
| 8932 | 9 ## |
| 10 ## Octave is distributed in the hope that it will be useful, but | |
| 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 | |
|
8933
346fde2030b5
scripts/statistics/base/histc.m: update copyright notice to match the rest of Octave
Soren Hauberg <hauberg@gmail.com>
parents:
8932
diff
changeset
|
16 ## along with Octave; see the file COPYING. If not, see |
|
346fde2030b5
scripts/statistics/base/histc.m: update copyright notice to match the rest of Octave
Soren Hauberg <hauberg@gmail.com>
parents:
8932
diff
changeset
|
17 ## <http://www.gnu.org/licenses/>. |
| 8932 | 18 |
| 19 ## -*- texinfo -*- | |
| 20 ## @deftypefn {Function File} {@var{n} =} histc (@var{y}, @var{edges}) | |
| 21 ## @deftypefnx {Function File} {@var{n} =} histc (@var{y}, @var{edges}, @var{dim}) | |
| 22 ## @deftypefnx {Function File} {[@var{n}, @var{idx}] =} histc (...) | |
| 23 ## Produce histogram counts. | |
| 24 ## | |
| 25 ## When @var{y} is a vector, the function counts the number of elements of | |
| 26 ## @var{y} that fall in the histogram bins defined by @var{edges}. This must be | |
| 27 ## a vector of monotonically non-decreasing values that define the edges of the | |
| 28 ## histogram bins. So, @code{@var{n} (k)} contains the number of elements in | |
| 29 ## @var{y} for which @code{@var{edges} (k) <= @var{y} < @var{edges} (k+1)}. | |
| 30 ## The final element of @var{n} contains the number of elements of @var{y} | |
| 31 ## that was equal to the last element of @var{edges}. | |
| 32 ## | |
| 33 ## When @var{y} is a @math{N}-dimensional array, the same operation as above is | |
| 34 ## repeated along dimension @var{dim}. If this argument is given, the operation | |
| 35 ## is performed along the first non-singleton dimension. | |
| 36 ## | |
| 37 ## If a second output argument is requested an index matrix is also returned. | |
| 38 ## The @var{idx} matrix has same size as @var{y}. Each element of @var{idx} | |
| 39 ## contains the index of the histogram bin in which the corresponding element | |
| 40 ## of @var{y} was counted. | |
| 41 ## | |
| 42 ## @seealso{hist} | |
| 43 ## @end deftypefn | |
| 44 | |
| 45 function [n, idx] = histc (data, edges, dim) | |
| 46 ## Check input | |
| 47 if (nargin < 2) | |
| 48 print_usage (); | |
| 49 endif | |
| 50 | |
| 51 sz = size (data); | |
| 52 if (nargin < 3) | |
| 53 dim = find (sz > 1, 1); | |
| 54 endif | |
| 55 | |
| 56 if (!isreal (data)) | |
| 57 error ("histc: first argument must be real a vector"); | |
| 58 endif | |
| 59 | |
| 60 ## Make sure 'edges' is sorted | |
| 61 num_edges = numel (edges); | |
| 62 if (isreal (edges)) | |
| 63 edges = edges (:); | |
| 64 tmp = sort (edges); | |
| 65 if (any (tmp != edges)) | |
| 66 warning ("histc: edge values not sorted on input"); | |
| 67 edges = tmp; | |
| 68 endif | |
| 69 else | |
| 70 error ("histc: second argument must be a vector"); | |
| 71 endif | |
| 72 | |
| 73 ## Allocate the histogram | |
| 74 nsz = sz; | |
| 75 nsz (dim) = num_edges; | |
| 76 n = zeros (nsz); | |
| 77 | |
| 78 ## Allocate 'idx' | |
| 79 if (nargout > 1) | |
| 80 idx = zeros (sz); | |
| 81 endif | |
| 82 | |
| 83 ## Prepare indices | |
| 84 idx1 = cell (1, dim-1); | |
| 85 for k = 1:length (idx1) | |
| 86 idx1 {k} = 1:sz (k); | |
| 87 endfor | |
| 88 idx2 = cell (length (sz) - dim); | |
| 89 for k = 1:length (idx2) | |
| 90 idx2 {k} = 1:sz (k+dim); | |
| 91 endfor | |
| 92 | |
| 93 ## Compute the histograms | |
| 94 for k = 1:num_edges-1 | |
| 95 b = (edges (k) <= data & data < edges (k+1)); | |
| 96 n (idx1 {:}, k, idx2 {:}) = sum (b, dim); | |
| 97 if (nargout > 1) | |
| 98 idx (b) = k; | |
| 99 endif | |
| 100 endfor | |
| 101 b = (data == edges (end)); | |
| 102 n (idx1 {:}, num_edges, idx2 {:}) = sum (b, dim); | |
| 103 if (nargout > 1) | |
| 104 idx (b) = num_edges; | |
| 105 endif | |
| 106 | |
| 107 endfunction | |
| 108 | |
| 109 %!test | |
| 110 %! data = linspace (0, 10, 1001); | |
| 111 %! n = histc (data, 0:10); | |
| 112 %! assert (n, [repmat(100, 1, 10), 1]); | |
| 113 | |
| 114 %!test | |
| 115 %! data = repmat (linspace (0, 10, 1001), [2, 1, 3]); | |
| 116 %! n = histc (data, 0:10, 2); | |
| 117 %! assert (n, repmat ([repmat(100, 1, 10), 1], [2, 1, 3])); | |
| 118 |