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view scripts/general/idivide.m @ 27919:1891570abac8
update Octave Project Developers copyright for the new year
In files that have the "Octave Project Developers" copyright notice,
update for 2020.
author | John W. Eaton <jwe@octave.org> |
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date | Mon, 06 Jan 2020 22:29:51 -0500 |
parents | b442ec6dda5c |
children | bd51beb6205e |
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## Copyright (C) 2008-2020 The Octave Project Developers ## ## See the file COPYRIGHT.md in the top-level directory of this distribution ## or <https://octave.org/COPYRIGHT.html/>. ## ## ## This file is part of Octave. ## ## Octave 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. ## ## Octave is distributed in the hope that it will be useful, but ## WITHOUT ANY WARRANTY; without even the implied warranty of ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ## GNU General Public License for more details. ## ## You should have received a copy of the GNU General Public License ## along with Octave; see the file COPYING. If not, see ## <https://www.gnu.org/licenses/>. ## -*- texinfo -*- ## @deftypefn {} {} idivide (@var{x}, @var{y}, @var{op}) ## Integer division with different rounding rules. ## ## The standard behavior of integer division such as @code{@var{a} ./ @var{b}} ## is to round the result to the nearest integer. This is not always the ## desired behavior and @code{idivide} permits integer element-by-element ## division to be performed with different treatment for the fractional ## part of the division as determined by the @var{op} flag. @var{op} is ## a string with one of the values: ## ## @table @asis ## @item @qcode{"fix"} ## Calculate @code{@var{a} ./ @var{b}} with the fractional part rounded ## towards zero. ## ## @item @qcode{"round"} ## Calculate @code{@var{a} ./ @var{b}} with the fractional part rounded ## towards the nearest integer. ## ## @item @qcode{"floor"} ## Calculate @code{@var{a} ./ @var{b}} with the fractional part rounded ## towards negative infinity. ## ## @item @qcode{"ceil"} ## Calculate @code{@var{a} ./ @var{b}} with the fractional part rounded ## towards positive infinity. ## @end table ## ## @noindent ## If @var{op} is not given it defaults to @qcode{"fix"}. ## An example demonstrating these rounding rules is ## ## @example ## @group ## idivide (int8 ([-3, 3]), int8 (4), "fix") ## @result{} 0 0 ## idivide (int8 ([-3, 3]), int8 (4), "round") ## @result{} -1 1 ## idivide (int8 ([-3, 3]), int8 (4), "floor") ## @result{} -1 0 ## idivide (int8 ([-3, 3]), int8 (4), "ceil") ## @result{} 0 1 ## @end group ## @end example ## ## @seealso{ldivide, rdivide} ## @end deftypefn function z = idivide (x, y, op) if (nargin < 2 || nargin > 3) print_usage (); endif if (nargin == 2) op = "fix"; else op = tolower (op); endif if (isfloat (x)) if (isinteger (y)) typ = class (y); else error ("idivide: at least one input (X or Y) must be an integer type"); endif elseif (isfloat (y)) if (isinteger (x)) typ = class (x); else error ("idivide: at least one input (X or Y) must be an integer type"); endif else typ = class (x); if (! strcmp (typ, class (y))) error ("idivide: integer type of X (%s) must match integer type of Y (%s)", typ, class (y)); endif endif if (strcmp (op, "fix")) z = cast (fix (double (x) ./ double (y)), typ); elseif (strcmp (op, "round")) z = x ./ y; elseif (strcmp (op, "floor")) z = cast (floor (double (x) ./ double (y)), typ); elseif (strcmp (op, "ceil")) z = cast (ceil (double (x) ./ double (y)), typ); else error ('idivide: unrecognized rounding type "%s"', op); endif endfunction %!shared a, af, b, bf %! a = int8 (3); %! af = 3; %! b = int8 ([-4, 4]); %! bf = [-4, 4]; %!assert (idivide (a, b), int8 ([0, 0])) %!assert (idivide (a, b, "floor"), int8 ([-1, 0])) %!assert (idivide (a, b, "ceil"), int8 ([0, 1])) %!assert (idivide (a, b, "round"), int8 ([-1, 1])) %!assert (idivide (af, b), int8 ([0, 0])) %!assert (idivide (af, b, "floor"), int8 ([-1, 0])) %!assert (idivide (af, b, "ceil"), int8 ([0, 1])) %!assert (idivide (af, b, "round"), int8 ([-1, 1])) %!assert (idivide (a, bf), int8 ([0, 0])) %!assert (idivide (a, bf, "floor"), int8 ([-1, 0])) %!assert (idivide (a, bf, "ceil"), int8 ([0, 1])) %!assert (idivide (a, bf, "round"), int8 ([-1, 1])) ## Test input validation %!error idivide (uint8 (1)) %!error idivide (uint8 (1), 2, 3) %!error <at least one input> idivide (1, 2) %!error <at least one input> idivide ({1}, 2) %!error <X \(int8\) must match.* Y \(uint8\)> idivide (int8 (1), uint8 (2)) %!error <unrecognized rounding type "foo"> idivide (int8 (1), 2, "foo")