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comparison scripts/strings/dec2bin.m @ 28236:5bb1c0cbb27e

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dec2bin.m: Allow negative number inputs (bug #58147). * dec2bin.m: Document that negative numbers are converted according to 2's complement convention. Add example to documentation of converting a negative number. Add algorithm to detect negative inputs and add the appropriate offset for 2's complement notation. Add BIST tests.
author Nicholas R. Jankowski <jankowskin@asme.org>
date Wed, 22 Apr 2020 15:53:51 -0700
parents 9f9ac219896d
children ac3a078e688f
comparison
equal deleted inserted replaced
28235:a6edb8097ec6 28236:5bb1c0cbb27e
23 ## 23 ##
24 ######################################################################## 24 ########################################################################
25 25
26 ## -*- texinfo -*- 26 ## -*- texinfo -*-
27 ## @deftypefn {} {} dec2bin (@var{d}, @var{len}) 27 ## @deftypefn {} {} dec2bin (@var{d}, @var{len})
28 ## Return a binary number corresponding to the non-negative integer @var{d}, 28 ## Return a binary number corresponding to the integer @var{d} as a string of
29 ## as a string of ones and zeros. 29 ## ones and zeros. If @var{d} is negative, return the two's complement binary
30 ## value of @var{d}.
30 ## 31 ##
31 ## For example: 32 ## For example:
32 ## 33 ##
33 ## @example 34 ## @example
34 ## @group 35 ## @group
35 ## dec2bin (14) 36 ## dec2bin (14)
36 ## @result{} "1110" 37 ## @result{} "1110"
38 ##
39 ## dec2bin (-14)
40 ## @result{} "11110010"
37 ## @end group 41 ## @end group
38 ## @end example 42 ## @end example
39 ## 43 ##
40 ## If @var{d} is a matrix or cell array, return a string matrix with one row 44 ## If @var{d} is a matrix or cell array, return a string matrix with one row
41 ## per element in @var{d}, padded with leading zeros to the width of the 45 ## per element in @var{d}, padded with leading zeros to the width of the
42 ## largest value. 46 ## largest value.
43 ## 47 ##
44 ## The optional second argument, @var{len}, specifies the minimum number of 48 ## The optional second argument, @var{len}, specifies the minimum number of
45 ## digits in the result. 49 ## digits in the result.
50 ##
46 ## @seealso{bin2dec, dec2base, dec2hex} 51 ## @seealso{bin2dec, dec2base, dec2hex}
47 ## @end deftypefn 52 ## @end deftypefn
48 53
49 function b = dec2bin (d, len) 54 function b = dec2bin (d, len)
55
56 ## dec2base does cell->mat conversion, this allows easier content comparison
57 if (iscell (d))
58 d = cell2mat (d);
59 endif
60
61 d = d(:); ## output is always a column vector, (:) simplifies value checks
62
63 if (any (d < intmin ("int64")))
64 error ("dec2bin: negative inputs cannot be less than intmin('int64')");
65 endif
66
67 if (any (d < 0))
68 if (any (d < intmin ("int64")))
69 error ("out of range");
70 elseif (any (d < intmin ("int32")))
71 d(d < 0) += double (intmax ("uint64")) + 1 ;
72 elseif (any (d < intmin ("int16")))
73 d(d < 0) += double (intmax ("uint32")) + 1;
74 elseif (any (d < intmin ("int8")))
75 d(d < 0) += double (intmax ("uint16"))+ 1;
76 else
77 d(d < 0) += double (intmax ("uint8")) +1;
78 endif
79 endif
50 80
51 if (nargin == 1) 81 if (nargin == 1)
52 b = dec2base (d, 2); 82 b = dec2base (d, 2);
53 elseif (nargin == 2) 83 elseif (nargin == 2)
54 b = dec2base (d, 2, len); 84 b = dec2base (d, 2, len);
57 endif 87 endif
58 88
59 endfunction 89 endfunction
60 90
61 91
92 %!assert (dec2bin (3), "11")
62 %!assert (dec2bin (14), "1110") 93 %!assert (dec2bin (14), "1110")
63 %!assert (dec2bin (14, 6), "001110") 94 %!assert (dec2bin (14, 6), "001110")
95 %!assert (dec2bin ([1, 2; 3, 4]), ["001"; "011"; "010"; "100"])
64 %!assert (dec2bin ({1, 2; 3, 4}), ["001"; "011"; "010"; "100"]) 96 %!assert (dec2bin ({1, 2; 3, 4}), ["001"; "011"; "010"; "100"])
97 %!assert (dec2bin ({1, 2; 3, 4}, 4), ["0001"; "0011"; "0010"; "0100"])
98
99 ## Test negative inputs
100 %!assert (dec2bin (-3), "11111101")
101 %!assert (dec2bin (-3, 3), "11111101")
102 %!assert (dec2bin (-3, 9), "011111101")
103 %!assert (dec2bin (-129), "1111111101111111")
104 %!assert (dec2bin (-2^15 -1), "11111111111111110111111111111111")
105 %!assert (dec2bin (-2^31 -1), "1111111111111111111111111111111101111111111111111111111111111111")
106 %!assert (dec2bin (-2^63), "1000000000000000000000000000000000000000000000000000000000000000")
107 %!assert (dec2bin (-2^63-1), "1000000000000000000000000000000000000000000000000000000000000000")
108 %!assert (dec2bin ([-1, -2; -3, -4]), ["11111111"; "11111101"; "11111110"; "11111100"])
109 %!assert (dec2bin ([1, 2; 3, -4]), ["00000001"; "00000011"; "00000010"; "11111100"])
110 %!assert (dec2bin ({1, 2; 3, -4}), ["00000001"; "00000011"; "00000010"; "11111100"])
65 111
66 ## Test input validation 112 ## Test input validation
67 %!error dec2bin () 113 %!error dec2bin ()
68 %!error dec2bin (1, 2, 3) 114 %!error dec2bin (1, 2, 3)
115 %!error dec2bin (2 * double (intmin ("int64")))