Mercurial > hg > octave-nkf
annotate scripts/general/idivide.m @ 10412:d2ac9433cd09
append AM_CPPFLAGS to libcruft_la_CPPFLAGS
| author | John W. Eaton <jwe@octave.org> |
|---|---|
| date | Mon, 15 Mar 2010 16:56:14 -0400 |
| parents | 16f53d29049f |
| children | 95c3e38098bf |
| rev | line source |
|---|---|
| 9245 | 1 ## Copyright (C) 2008, 2009 David Bateman |
| 7627 | 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 | |
| 7 ## the Free Software Foundation; either version 3 of the License, or (at | |
| 8 ## your option) any later version. | |
| 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 | |
| 16 ## along with Octave; see the file COPYING. If not, see | |
| 17 ## <http://www.gnu.org/licenses/>. | |
| 18 | |
| 19 ## -*- texinfo -*- | |
| 20 ## @deftypefn {Function File} {} idivide (@var{x}, @var{y}, @var{op}) | |
|
9036
58604c45ca74
Cleanup of data types related documentation
Rik <rdrider0-list@yahoo.com>
parents:
7627
diff
changeset
|
21 ## Integer division with different round rules. The standard behavior of |
| 7627 | 22 ## the an integer division such as @code{@var{a} ./ @var{b}} is to round |
|
9036
58604c45ca74
Cleanup of data types related documentation
Rik <rdrider0-list@yahoo.com>
parents:
7627
diff
changeset
|
23 ## the result to the nearest integer. This is not always the desired |
| 7627 | 24 ## behavior and @code{idivide} permits integer element-by-element |
| 25 ## division to be performed with different treatment for the fractional | |
|
9036
58604c45ca74
Cleanup of data types related documentation
Rik <rdrider0-list@yahoo.com>
parents:
7627
diff
changeset
|
26 ## part of the division as determined by the @var{op} flag. @var{op} is |
| 7627 | 27 ## a string with one of the values: |
| 28 ## | |
| 29 ## @table @asis | |
| 30 ## @item "fix" | |
| 31 ## Calculate @code{@var{a} ./ @var{b}} with the fractional part rounded | |
| 32 ## towards zero. | |
| 33 ## @item "round" | |
| 34 ## Calculate @code{@var{a} ./ @var{b}} with the fractional part rounded | |
| 35 ## towards the nearest integer. | |
| 36 ## @item "floor" | |
| 37 ## Calculate @code{@var{a} ./ @var{b}} with the fractional part rounded | |
| 38 ## downwards. | |
| 39 ## @item "ceil" | |
| 40 ## Calculate @code{@var{a} ./ @var{b}} with the fractional part rounded | |
| 41 ## upwards. | |
| 42 ## @end table | |
| 43 ## | |
| 44 ## @noindent | |
| 45 ## If @var{op} is not given it is assumed that it is @code{"fix"}. | |
| 46 ## An example demonstrating these rounding rules is | |
| 47 ## | |
| 48 ## @example | |
|
9051
1bf0ce0930be
Grammar check TexInfo in all .m files
Rik <rdrider0-list@yahoo.com>
parents:
9036
diff
changeset
|
49 ## @group |
| 7627 | 50 ## idivide (int8 ([-3, 3]), int8 (4), "fix") |
| 51 ## @result{} int8 ([0, 0]) | |
| 52 ## idivide (int8 ([-3, 3]), int8 (4), "round") | |
| 53 ## @result{} int8 ([-1, 1]) | |
| 54 ## idivide (int8 ([-3, 3]), int8 (4), "ceil") | |
| 55 ## @result{} int8 ([0, 1]) | |
| 56 ## idivide (int8 ([-3, 3]), int8 (4), "floor") | |
| 57 ## @result{} int8 ([-1, 0]) | |
|
9051
1bf0ce0930be
Grammar check TexInfo in all .m files
Rik <rdrider0-list@yahoo.com>
parents:
9036
diff
changeset
|
58 ## @end group |
| 7627 | 59 ## @end example |
| 60 ## | |
| 61 ## @seealso{ldivide, rdivide} | |
| 62 ## @end deftypefn | |
| 63 | |
| 64 function z = idivide (x, y, op) | |
| 65 if (nargin < 2 || nargin > 3) | |
| 66 print_usage (); | |
| 67 elseif (nargin == 2) | |
| 68 op = "fix"; | |
| 69 else | |
| 70 op = tolower (op); | |
| 71 endif | |
| 72 | |
| 73 if (strcmp (op, "round")) | |
| 74 z = x ./ y; | |
| 75 else | |
| 76 if (isfloat (x)) | |
| 77 typ = class (y); | |
| 78 elseif (isfloat (y)) | |
| 79 typ = class (x); | |
| 80 else | |
| 81 typ = class (x); | |
| 82 if (!strcmp (class (x), class (y))) | |
| 83 error ("idivide: incompatible types"); | |
| 84 endif | |
| 85 endif | |
| 86 | |
| 87 if (strcmp (op, "fix")) | |
| 88 z = cast (fix (double (x) ./ double (y)), typ); | |
| 89 elseif (strcmp (op, "floor")) | |
| 90 z = cast (floor (double (x) ./ double (y)), typ); | |
| 91 elseif (strcmp (op, "ceil")) | |
| 92 z = cast (ceil (double (x) ./ double (y)), typ); | |
| 93 else | |
| 94 error ("idivide: unrecognized rounding type"); | |
| 95 endif | |
| 96 endif | |
| 97 endfunction | |
| 98 | |
| 99 %!shared a, af, b, bf | |
| 100 %! a = int8(3); | |
| 101 %! af = 3; | |
| 102 %! b = int8([-4, 4]); | |
| 103 %! bf = [-4, 4]; | |
| 104 | |
| 105 %!assert (idivide (a, b), int8 ([0, 0])) | |
| 106 %!assert (idivide (a, b, "floor"), int8([-1, 0])) | |
| 107 %!assert (idivide (a, b, "ceil"), int8 ([0, 1])) | |
| 108 %!assert (idivide (a, b, "round"), int8 ([-1, 1])) | |
| 109 | |
| 110 %!assert (idivide (af, b), int8 ([0, 0])) | |
| 111 %!assert (idivide (af, b, "floor"), int8([-1, 0])) | |
| 112 %!assert (idivide (af, b, "ceil"), int8 ([0, 1])) | |
| 113 %!assert (idivide (af, b, "round"), int8 ([-1, 1])) | |
| 114 | |
| 115 %!assert (idivide (a, bf), int8 ([0, 0])) | |
| 116 %!assert (idivide (a, bf, "floor"), int8([-1, 0])) | |
| 117 %!assert (idivide (a, bf, "ceil"), int8 ([0, 1])) | |
| 118 %!assert (idivide (a, bf, "round"), int8 ([-1, 1])) | |
| 119 | |
| 120 %!error (idivide (uint8(1), int8(1))) |