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authornobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2014-05-04 01:23:01 +0000
committernobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2014-05-04 01:23:01 +0000
commit7a6ebecf9ea5d00ccde2d78d45d35aaff3866845 (patch)
treee13381d3405b3685d7f1826debf75fe3106bb855
parent6e34259271c705b3d8bb300b5374addb51dce5a0 (diff)
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 <cremno AT mail.ru> in [ruby-core:62310]. [Feature #9799] git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45805 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
-rw-r--r--ChangeLog6
-rw-r--r--NEWS2
-rw-r--r--configure.in1
-rw-r--r--math.c19
-rw-r--r--test/ruby/test_math.rb13
5 files changed, 36 insertions, 5 deletions
diff --git a/ChangeLog b/ChangeLog
index d6c0625..99ce763 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Sun May 4 10:22:59 2014 Nobuyoshi Nakada <nobu@ruby-lang.org>
+
+ * math.c (math_atan2): return values like as expected by C99 if
+ both two arguments are infinity. based on the patch by cremno
+ phobia <cremno AT mail.ru> in [ruby-core:62310]. [Feature #9799]
+
Sun May 4 03:46:42 2014 Tanaka Akira <akr@fsij.org>
* lib/time.rb (Time.httpdate): Always return a UTC Time object.
diff --git a/NEWS b/NEWS
index 22494be..06b265a 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 1258daa..57bb400 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 70cd26c..b042e7d 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 2eaea6c..4d819d7 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))