Mercurial > octave-libtiff

comparison scripts/specfun/nchoosek.m @ 30209:54774a713d7c

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
nchoosek.m: Improve struct input handling for k<n (bug #61119) * nchoosek.m: replace call to repelems with repelem to handle struct inputs for k<n. Add k<n struct BIST test.
author Nicholas R. Jankowski <jankowskin@asme.org>
date Thu, 23 Sep 2021 21:06:41 -0400
parents aaee7b170cb1
children f5aba4d7e651
comparison
equal deleted inserted replaced
30208:8f61866f0f6d 30209:54774a713d7c
125 C = v(:).'; 125 C = v(:).';
126 elseif (k > n) 126 elseif (k > n)
127 C = v(zeros (0, k)); # return 0xk object for Matlab compatibility 127 C = v(zeros (0, k)); # return 0xk object for Matlab compatibility
128 elseif (k == 2) 128 elseif (k == 2)
129 ## Can do it without transpose. 129 ## Can do it without transpose.
130 x = repelems (v(1:n-1), [1:n-1; n-1:-1:1]).'; 130 x = repelem (v(1:n-1), [n-1:-1:1]).';
131 y = cat (1, cellslices (v(:), 2:n, n*ones (1, n-1)){:}); 131 y = cat (1, cellslices (v(:), 2:n, n*ones (1, n-1)){:});
132 C = [x, y]; 132 C = [x, y];
133 elseif (k < n) 133 elseif (k < n)
134 v = v(:).'; 134 v = v(:).';
135 C = v(k:n); 135 C = v(k:n);
136 l = 1:n-k+1; 136 l = 1:n-k+1;
137 for j = 2:k 137 for j = 2:k
138 c = columns (C); 138 c = columns (C);
139 cA = cellslices (C, l, c*ones (1, n-k+1), 2); 139 cA = cellslices (C, l, c*ones (1, n-k+1), 2);
140 l = c-l+1; 140 l = c-l+1;
141 b = repelems (v(k-j+1:n-j+1), [1:n-k+1; l]); 141 b = repelem (v(k-j+1:n-j+1), l);
142 C = [b; cA{:}]; 142 C = [b; cA{:}];
143 l = cumsum (l); 143 l = cumsum (l);
144 l = [1, 1 + l(1:n-k)]; 144 l = [1, 1 + l(1:n-k)];
145 endfor 145 endfor
146 C = C.'; 146 C = C.';
158 %!assert (nchoosek ("a":"b", 2), "ab") 158 %!assert (nchoosek ("a":"b", 2), "ab")
159 %!assert (nchoosek ({1,2}, 2), {1,2}) 159 %!assert (nchoosek ({1,2}, 2), {1,2})
160 %!test 160 %!test
161 %! s(1).a = 1; 161 %! s(1).a = 1;
162 %! s(2).a = 2; 162 %! s(2).a = 2;
163 %! assert (nchoosek (s, 1), s(:)); 163 %! assert (nchoosek (s, 1), s(:));
164 %! assert (nchoosek (s, 2), s); 164 %! assert (nchoosek (s, 2), s);
165 165
166 # Verify Matlab compatibility of return sizes & types 166 # Verify Matlab compatibility of return sizes & types
167 %!test 167 %!test
168 %! x = nchoosek (1:2, 0); 168 %! x = nchoosek (1:2, 0);
169 %! assert (size (x), [1, 0]); 169 %! assert (size (x), [1, 0]);
226 226
227 %!test 227 %!test
228 %! s.a = [1 2 3]; 228 %! s.a = [1 2 3];
229 %! s.b = [4 5 6]; 229 %! s.b = [4 5 6];
230 %! s(2).a = 1; # make s a struct array rather than scalar struct 230 %! s(2).a = 1; # make s a struct array rather than scalar struct
231 %! s(3).b = 2; # make s at least three elements for k == 2 test below
231 %! x = nchoosek (s, 0); 232 %! x = nchoosek (s, 0);
232 %! assert (size (x), [1, 0]); 233 %! assert (size (x), [1, 0]);
233 %! assert (isstruct (x)); 234 %! assert (isstruct (x));
234 %! assert (fieldnames (x), {"a"; "b"}); 235 %! assert (fieldnames (x), {"a"; "b"});
235 %! x = nchoosek (s, 3); 236 %! x = nchoosek (s, 2);
236 %! assert (size (x), [0, 3]); 237 %! assert (size (x), [3, 2]);
238 %! assert (isstruct (x));
239 %! assert (fieldnames (x), {"a"; "b"});
240 %! x = nchoosek (s, 4);
241 %! assert (size (x), [0, 4]);
237 %! assert (isstruct (x)); 242 %! assert (isstruct (x));
238 %! assert (fieldnames (x), {"a"; "b"}); 243 %! assert (fieldnames (x), {"a"; "b"});
239 244
240 ## Test input validation 245 ## Test input validation
241 %!error <Invalid call> nchoosek () 246 %!error <Invalid call> nchoosek ()