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comparison scripts/special-matrix/magic.m @ 25235:27e6b38571d3

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magic.m: Issue an error if input N is negative (bug #53441). * magic.m: Check for negative N and call error() if found. Add BIST test to check new code.
author Dildar Sk <dildarsk101010@gmail.com>
date Fri, 23 Mar 2018 19:03:45 -0400
parents 6652d3823428
children 00f796120a6d
comparison
equal deleted inserted replaced
25234:b02d5a4c7452 25235:27e6b38571d3
34 if (nargin != 1) 34 if (nargin != 1)
35 print_usage (); 35 print_usage ();
36 endif 36 endif
37 37
38 n = fix (n); 38 n = fix (n);
39 if (n < 1) 39 if (n < 0)
40 40 error ("magic: N must be non-negative");
41 elseif (n < 1)
41 A = []; 42 A = [];
42
43 elseif (mod (n, 2) == 1) 43 elseif (mod (n, 2) == 1)
44 44
45 shift = floor ((0:n*n-1)/n); 45 shift = floor ((0:n*n-1)/n);
46 c = mod ([1:n*n] - shift + (n-3)/2, n); 46 c = mod ([1:n*n] - shift + (n-3)/2, n);
47 r = mod ([n*n:-1:1] + 2*shift, n); 47 r = mod ([n*n:-1:1] + 2*shift, n);
89 ## While one day we may change the actual return of magic (2), 89 ## While one day we may change the actual return of magic (2),
90 ## this properties still must be true. 90 ## this properties still must be true.
91 %!test <*46672> 91 %!test <*46672>
92 %! m = magic (2); 92 %! m = magic (2);
93 %! assert (size (m), [2 2]); 93 %! assert (size (m), [2 2]);
94 %! assert (unique (m), [1; 2; 3; 4]); 94 %! assert (m, [4 3; 1 2]);
95 95
96 %!assert (magic (2), [4 3; 1 2])
97 %!assert (isempty (magic (-1)))
98 %!assert (isempty (magic (0))) 96 %!assert (isempty (magic (0)))
99 %!assert (magic (1), 1) 97 %!assert (magic (1), 1)
100 %!assert (magic (1.5), 1) 98 %!assert (magic (1.5), 1)
101 99
102 ## Test input validation 100 ## Test input validation
103 %!error magic () 101 %!error magic ()
104 %!error magic (1, 2) 102 %!error magic (1, 2)
103 %!error <N must be non-negative> magic (-5)