Added some unittests and cleanup (in statistics and linalg)

linalg/unittest_subspace_angles.m

@@ -0,0 +1,46 @@
+function unittest_subspace_angles
+% UNITTEST_SUBSPACE_ANGLES Test the SUBSPACE_ANGLES function.
+%
+% Example (<a href="matlab:run_example unittest_subspace_angles">run</a>)
+%   unittest_subspace_angle
+%
+% See also SUBSPACE_ANGLES, TESTSUITE 
+
+%   Elmar Zander
+%   Copyright 2010, Inst. of Scientific Computing, TU Braunschweig
+%   $Id$ 
+%
+%   This program 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. 
+%   See the GNU General Public License for more details. You should have
+%   received a copy of the GNU General Public License along with this
+%   program.  If not, see <http://www.gnu.org/licenses/>.
+
+munit_set_function( 'subspace_angles' );
+
+e1=unitvector(1,4);
+e2=unitvector(2,4);
+e3=unitvector(3,4);
+e4=unitvector(4,4);
+
+test([e1, e2], [e1, e2]);
+test([e1, e2], [e1, e3]);
+test([e1, e2], [e3, e4]);
+test([e1, e2], [e1, -e2+e4]);
+
+A=rand(7,5); B=rand(7,5); 
+assert_equals( asin(subspace_distance(A,B)), subspace(A,B) )
+A=[A, A]; B=[B, B];
+assert_equals( asin(subspace_distance(A,B)), subspace(A,B) )
+A=rand(7,5); B=rand(7,3); 
+assert_equals( asin(subspace_distance(A,B)), subspace(A,B) )
+A=rand(7,3); B=rand(7,5); 
+assert_equals( asin(subspace_distance(A,B)), subspace(A,B) )
+
+
+function test(A1,A2)
+theta=subspace_angles(A1,A2);
+dist=subspace_distance(A1,A2);
+assert_equals( dist, sin(theta(2)) );

linalg/unittest_subspace_distance.m

@@ -0,0 +1,49 @@
+function unittest_subspace_distance
+% UNITTEST_SUBSPACE_DISTANCE Test the SUBSPACE_DISTANCE function.
+%
+% Example (<a href="matlab:run_example unittest_subspace_distance">run</a>)
+%   unittest_subspace_distance
+%
+% See also SUBSPACE_DISTANCE, TESTSUITE 
+
+%   Elmar Zander
+%   Copyright 2013, Inst. of Scientific Computing, TU Braunschweig
+%
+%   This program 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. 
+%   See the GNU General Public License for more details. You should have
+%   received a copy of the GNU General Public License along with this
+%   program.  If not, see <http://www.gnu.org/licenses/>.
+
+munit_set_function( 'subspace_distance' );
+
+
+rand('seed', 74765); %#ok<RAND>
+
+N=10;
+A=rand(N,3);
+B=rand(N,5);
+
+assert_equals(subspace_distance(A,B), subspace_distance(B,A), 'symm');
+assert_equals(subspace_distance(A,B), sin(subspace(A,B)), 'mlab');
+assert_equals(subspace_distance(A,[B, A]), 0, 'zero');
+
+
+opts.type = 'gv';
+A=rand(N,3);
+B=rand(N,3);
+assert_equals(subspace_distance(A,B,opts), subspace_distance(B,A,opts), 'symm_gv');
+assert_equals(subspace_distance(A,B,opts), subspace_distance(A,B), 'same_as_mlab_if_same_size');
+assert_equals(subspace_distance(A,[B, A],opts), 1, 'one_gv');
+
+
+opts.type = 'wwf';
+A=rand(N,3);
+B=rand(N,3);
+assert_equals(subspace_distance(A,B,opts), subspace_distance(B,A,opts), 'symm_wwf');
+assert_equals(subspace_distance(A, A, opts), 0, 'zero_wwf');
+
+
+

gendist_fix_moments.m → statistics/gendist_fix_moments.m

@@ -1,10 +1,20 @@
 function [shift,scale]=gendist_fix_moments(dist, params, mean, var)
-% GENDIST_FIX_MOMENTS Short description of gendist_fix_moments.
-%   GENDIST_FIX_MOMENTS Long description of gendist_fix_moments.
+% GENDIST_FIX_MOMENTS Computes scale and shift to get specific moments.
+%   [SHIFT,SCALE]=GENDIST_FIX_MOMENTS(DIST, PARAMS, MEAN, VAR) computes
+%   shift and scale parameters such that the distribution specified by
+%   DIST, PARAMS, SHIFT and SCALE has mean MEAN and variance VAR.
 %
 % Example (<a href="matlab:run_example gendist_fix_moments">run</a>)
+%   dist = 'beta';
+%   params = {2, 4};
+%   [m, v] = gendist_moments(dist, params);
+%   fprintf( 'before: mu=%g, var=%g\n', m, v);
+%   
+%   [shift,scale]=gendist_fix_moments(dist, params, pi, exp(1));
+%   [m, v] = gendist_moments(dist, params, shift, scale);
+%   fprintf( 'after:  mu=%g, var=%g\n', m, v);
 %
-% See also
+% See also GENDIST_MOMENTS
 
 %   Elmar Zander
 %   Copyright 2010, Inst. of Scientific Computing, TU Braunschweig

statistics/private/scaled_distance.m

@@ -1,9 +1,34 @@
 function dist=scaled_distance(x1, x2, l, smooth, sqr)
-% SCALED_DISTANCE Short description of scaled_distance.
-%   SCALED_DISTANCE Long description of scaled_distance.
+% SCALED_DISTANCE Computes the scaled distance between points.
+%   DIST=SCALED_DISTANCE(X1, X2) computes the Euclidean distance between
+%   points given in X1 and X2.
 %
-% Example (<a href="matlab:run_example scaled_distance">run</a>)
+%   DIST=SCALED_DISTANCE(X1, X2, L) computes the Euclidean distance between
+%   X1 and X2 scaled by L where L can be scalar or a vector of the same
+%   dimension as the points in X1 and X2.
+%
+%   DIST=SCALED_DISTANCE(X1, X2, L, SMOOTH) computes the smoothed
+%   Euclidean distance where the smoothing function is given by
+%   D_SMOOTH=SQRT(D+SMOOTH^2)-SMOOTH.
+%   
+%   DIST=SCALED_DISTANCE(X1, X2, L, SMOOTH, SQR) returns the square of the
+%   Eudclidean smoothed, scaled distance. This saves computing the square
+%   root if only the square is needed by the calling code anyway.
 %
+%   Note: if an empty array is specified for a parameter the default value
+%   is used. DIST=SCALED_DISTANCE(X1, X2, [], [], TRUE) computes the square
+%   of the distance with parameters L and SMOOTH set to their defaults 1
+%   and 0.
+%
+% Example (<a href="matlab:run_example scaled_distance">run</a>)
+%     d=linspace(-1,1);
+%     plot(d, scaled_distance(d, [], [], 0)); hold all;
+%     plot(d, scaled_distance(d, [], [], 1));
+%     plot(d, scaled_distance(d, [], [], 2));
+%     plot(d, scaled_distance(d, [], 0.3, 0));
+%     plot(d, scaled_distance(d, [], 0.3, 1));
+%     plot(d, scaled_distance(d, [], 0.3, 2)); hold off;
+%     axis equal;
 % See also
 
 %   Elmar Zander
@@ -18,13 +43,13 @@
 %   received a copy of the GNU General Public License along with this
 %   program.  If not, see <http://www.gnu.org/licenses/>.
 
-if nargin<5
+if nargin<5 || isempty(sqr)
     sqr=false;
 end
-if nargin<4
+if nargin<4 || isempty(smooth)
     smooth=0;
 end
-if nargin<3
+if nargin<3 || isempty(l)
     l=1;
 end
 

unittest_gendist_fix_moments.m → statistics/unittest_gendist_fix_moments.m

@@ -20,10 +20,17 @@
 
 munit_set_function( 'gendist_fix_moments' );
 
+% can test directly for the normal and uniform distributions
+[shift,scale]=gendist_fix_moments( 'normal', {2, 5}, 7, 13 );
+assert_equals([shift,scale], [5, sqrt(13/25)], 'normal');
+
+[shift,scale]=gendist_fix_moments( 'uniform', {22, 88}, 50, 3 );
+assert_equals([shift,scale], [-5, 1/11], 'uniform');
+
+% can test via the moments for the lognormal distribution
 dist='lognormal';
 params={0,1};
 [shift,scale]=gendist_fix_moments( dist, params, 3.1, 2.4 );
 [mean,var]=gendist_moments( dist, params, shift, scale );
 assert_equals( mean, 3.1, 'mean' );
 assert_equals( var, 2.4, 'var' );
-