From 7a6ebecf9ea5d00ccde2d78d45d35aaff3866845 Mon Sep 17 00:00:00 2001 From: nobu Date: Sun, 4 May 2014 01:23:01 +0000 Subject: math.c: C99-like atan2 * math.c (math_atan2): return values like as expected by C99 if both two arguments are infinity. based on the patch by cremno phobia in [ruby-core:62310]. [Feature #9799] git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45805 b2dd03c8-39d4-4d8f-98ff-823fe69b080e --- ChangeLog | 6 ++++++ NEWS | 2 ++ configure.in | 1 + math.c | 19 ++++++++++++++++++- test/ruby/test_math.rb | 13 +++++++++---- 5 files changed, 36 insertions(+), 5 deletions(-) diff --git a/ChangeLog b/ChangeLog index d6c0625a54..99ce763d23 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,9 @@ +Sun May 4 10:22:59 2014 Nobuyoshi Nakada + + * math.c (math_atan2): return values like as expected by C99 if + both two arguments are infinity. based on the patch by cremno + phobia in [ruby-core:62310]. [Feature #9799] + Sun May 4 03:46:42 2014 Tanaka Akira * lib/time.rb (Time.httpdate): Always return a UTC Time object. diff --git a/NEWS b/NEWS index 22494bec25..06b265a45b 100644 --- a/NEWS +++ b/NEWS @@ -54,6 +54,8 @@ with all sufficient information, see the ChangeLog file. * Math.log now raises Math::DomainError instead of returning NaN if the base is less than 0, and returns NaN instead of -infinity if both of two arguments are 0. + * Math.atan2 now returns values like as expected by C99 if both two + arguments are infinity. * Proc * incompatible changes: diff --git a/configure.in b/configure.in index 1258daac42..57bb40086a 100644 --- a/configure.in +++ b/configure.in @@ -1941,6 +1941,7 @@ AC_CHECK_FUNCS(__syscall) AC_CHECK_FUNCS(_longjmp) # used for AC_ARG_WITH(setjmp-type) AC_CHECK_FUNCS(_setjmp) # used for AC_ARG_WITH(setjmp-type) AC_CHECK_FUNCS(_setjmpex) # used for AC_ARG_WITH(setjmp-type) +AC_CHECK_FUNCS(atan2l atan2f) AC_CHECK_FUNCS(chroot) AC_CHECK_FUNCS(chsize) AC_CHECK_FUNCS(clock_gettime) diff --git a/math.c b/math.c index 70cd26cb07..b042e7dbea 100644 --- a/math.c +++ b/math.c @@ -55,6 +55,10 @@ VALUE rb_eMathDomainError; * Math.atan2(1.0, 0.0) #=> 1.5707963267948966 * Math.atan2(1.0, -1.0) #=> 2.356194490192345 * Math.atan2(0.0, -1.0) #=> 3.141592653589793 + * Math.atan2(INFINITY, INFINITY) #=> 0.7853981633974483 + * Math.atan2(INFINITY, -INFINITY) #=> 2.356194490192345 + * Math.atan2(-INFINITY, INFINITY) #=> -0.7853981633974483 + * Math.atan2(-INFINITY, -INFINITY) #=> -2.356194490192345 * */ @@ -75,7 +79,20 @@ math_atan2(VALUE obj, VALUE y, VALUE x) return DBL2NUM(M_PI); return DBL2NUM(-M_PI); } - if (isinf(dx) && isinf(dy)) domain_error("atan2"); +#if !(defined(HAVE_ATAN2L) && defined(HAVE_ATAN2F)) || 1 + /* assume atan2() doesn't handle Inf as C99 */ + if (isinf(dx) && isinf(dy)) { + /* optimization for FLONUM */ + if (dx < 0.0) { + const double dz = (3.0 * M_PI / 4.0); + return (dy < 0.0) ? DBL2NUM(-dz) : DBL2NUM(dz); + } + else { + const double dz = (M_PI / 4.0); + return (dy < 0.0) ? DBL2NUM(-dz) : DBL2NUM(dz); + } + } +#endif return DBL2NUM(atan2(dy, dx)); } diff --git a/test/ruby/test_math.rb b/test/ruby/test_math.rb index 2eaea6cf37..4d819d71a1 100644 --- a/test/ruby/test_math.rb +++ b/test/ruby/test_math.rb @@ -22,10 +22,15 @@ class TestMath < Test::Unit::TestCase check(-0.0, Math.atan2(-0.0, +0.0)) check(+Math::PI, Math.atan2(+0.0, -0.0)) check(-Math::PI, Math.atan2(-0.0, -0.0)) - assert_raise(Math::DomainError) { Math.atan2(Float::INFINITY, Float::INFINITY) } - assert_raise(Math::DomainError) { Math.atan2(Float::INFINITY, -Float::INFINITY) } - assert_raise(Math::DomainError) { Math.atan2(-Float::INFINITY, Float::INFINITY) } - assert_raise(Math::DomainError) { Math.atan2(-Float::INFINITY, -Float::INFINITY) } + + inf = Float::INFINITY + expected = 3.0 * Math::PI / 4.0 + assert_nothing_raised { check(+expected, Math.atan2(+inf, -inf)) } + assert_nothing_raised { check(-expected, Math.atan2(-inf, -inf)) } + expected = Math::PI / 4.0 + assert_nothing_raised { check(+expected, Math.atan2(+inf, +inf)) } + assert_nothing_raised { check(-expected, Math.atan2(-inf, +inf)) } + check(0, Math.atan2(0, 1)) check(Math::PI / 4, Math.atan2(1, 1)) check(Math::PI / 2, Math.atan2(1, 0)) -- cgit v1.2.3