зеркало из https://github.com/github/ruby.git
* configure.in: Check nextafter() availability.
* include/ruby/missing.h (nextafter): New optional declaration. * missing/nextafter.c: New file. * numeric.c: Float#next_float and Float#prev_float implemented. [ruby-core:62562] [Feature #9834] git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45982 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
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Коммит
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12
ChangeLog
12
ChangeLog
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@ -1,3 +1,15 @@
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Sun May 18 09:16:33 2014 Tanaka Akira <akr@fsij.org>
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* configure.in: Check nextafter() availability.
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* include/ruby/missing.h (nextafter): New optional declaration.
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* missing/nextafter.c: New file.
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* numeric.c: Float#next_float and Float#prev_float implemented.
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[ruby-core:62562] [Feature #9834]
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Sun May 18 09:02:17 2014 Tanaka Akira <akr@fsij.org>
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* enum.c: Enumerable#slice_after implemented.
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5
NEWS
5
NEWS
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@ -25,6 +25,11 @@ with all sufficient information, see the ChangeLog file.
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* File
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* new class File::Statfs to hold filesystem information. (experimental)
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* Float
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* New methods:
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* Float#next_float
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* Float#prev_float
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* IO
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* New methods
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* IO#statfs returns filesystem information as File::Statfs. (experimental)
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@ -1934,6 +1934,7 @@ AC_REPLACE_FUNCS(isinf)
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AC_REPLACE_FUNCS(isnan)
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AC_REPLACE_FUNCS(lgamma_r)
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AC_REPLACE_FUNCS(memmove)
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AC_REPLACE_FUNCS(nextafter)
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AC_REPLACE_FUNCS(setproctitle)
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AC_REPLACE_FUNCS(strchr)
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AC_REPLACE_FUNCS(strerror)
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@ -0,0 +1,3 @@
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$(OBJS): $(HDRS) $(ruby_headers)
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nextafter.o: nextafter.c $(top_srcdir)/missing/nextafter.c
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@ -0,0 +1,7 @@
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$INCFLAGS << " -I$(topdir) -I$(top_srcdir)"
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$srcs = Dir[File.join($srcdir, "*.{#{SRC_EXT.join(%q{,})}}")]
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inits = $srcs.map {|s| File.basename(s, ".*")}
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inits.delete("init")
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inits.map! {|s|"X(#{s})"}
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$defs << "-DTEST_INIT_FUNCS(X)=\"#{inits.join(' ')}\""
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create_makefile("-test-/float")
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@ -0,0 +1,11 @@
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#include "ruby.h"
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#define init(n) {void Init_##n(VALUE klass); Init_##n(klass);}
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void
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Init_float(void)
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{
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VALUE mBug = rb_define_module("Bug");
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VALUE klass = rb_define_class_under(mBug, "Float", rb_cObject);
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TEST_INIT_FUNCS(init);
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}
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@ -0,0 +1,36 @@
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#include "ruby.h"
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static VALUE
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system_nextafter_m(VALUE klass, VALUE vx, VALUE vy)
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{
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double x, y, z;
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x = NUM2DBL(vx);
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y = NUM2DBL(vy);
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z = nextafter(x, y);
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return DBL2NUM(z);
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}
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#define nextafter missing_nextafter
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#include "../../../missing/nextafter.c"
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#undef nextafter
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static VALUE
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missing_nextafter_m(VALUE klass, VALUE vx, VALUE vy)
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{
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double x, y, z;
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x = NUM2DBL(vx);
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y = NUM2DBL(vy);
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z = missing_nextafter(x, y);
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return DBL2NUM(z);
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}
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void
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Init_nextafter(VALUE klass)
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{
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rb_define_singleton_method(klass, "system_nextafter", system_nextafter_m, 2);
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rb_define_singleton_method(klass, "missing_nextafter", missing_nextafter_m, 2);
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}
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@ -168,6 +168,10 @@ RUBY_EXTERN int isnan(double);
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# endif
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#endif
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#ifndef HAVE_NEXTAFTER
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RUBY_EXTERN double nextafter(double x, double y);
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#endif
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/*
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#ifndef HAVE_MEMCMP
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RUBY_EXTERN int memcmp(const void *, const void *, size_t);
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@ -0,0 +1,75 @@
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#include <math.h>
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#include <float.h>
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/* This function doesn't set errno. It should on POSIX, though. */
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double
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nextafter(double x, double y)
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{
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double x1, x2, d;
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int e;
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if (isnan(x))
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return x;
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if (isnan(y))
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return y;
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if (x == y)
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return y;
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if (x == 0) {
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/* the minimum "subnormal" float */
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x1 = ldexp(0.5, DBL_MIN_EXP - DBL_MANT_DIG + 1);
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if (x1 == 0)
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x1 = DBL_MIN; /* the minimum "normal" float */
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if (0 < y)
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return x1;
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else
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return -x1;
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}
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if (x < 0) {
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if (isinf(x))
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return -DBL_MAX;
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if (x == -DBL_MAX && y < 0 && isinf(y))
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return y;
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}
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else {
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if (isinf(x))
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return DBL_MAX;
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if (x == DBL_MAX && 0 < y && isinf(y))
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return y;
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}
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x1 = frexp(x, &e);
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if (x < y) {
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d = DBL_EPSILON/2;
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if (x1 == -0.5) {
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x1 *= 2;
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e--;
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}
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}
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else {
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d = -DBL_EPSILON/2;
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if (x1 == 0.5) {
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x1 *= 2;
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e--;
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}
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}
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if (e < DBL_MIN_EXP) {
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d = ldexp(d, DBL_MIN_EXP-e);
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}
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x2 = x1 + d;
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if (x2 == 0.0) {
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if (x1 < 0)
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return -0.0;
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else
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return +0.0;
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}
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return ldexp(x2, e);
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}
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115
numeric.c
115
numeric.c
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@ -1478,6 +1478,119 @@ flo_is_finite_p(VALUE num)
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return Qtrue;
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}
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/*
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* call-seq:
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* float.next_float -> float
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*
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* Returns the next representable floating-point number.
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*
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* Float::MAX.next_float and Float::INFINITY.next_float is Float::INFINITY.
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*
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* Float::NAN.next_float is Float::NAN.
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*
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* For example:
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*
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* p 0.01.next_float #=> 0.010000000000000002
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* p 1.0.next_float #=> 1.0000000000000002
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* p 100.0.next_float #=> 100.00000000000001
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*
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* p 0.01.next_float - 0.01 #=> 1.734723475976807e-18
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* p 1.0.next_float - 1.0 #=> 2.220446049250313e-16
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* p 100.0.next_float - 100.0 #=> 1.4210854715202004e-14
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*
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* f = 0.01; 20.times { printf "%-20a %s\n", f, f.to_s; f = f.next_float }
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* #=> 0x1.47ae147ae147bp-7 0.01
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* # 0x1.47ae147ae147cp-7 0.010000000000000002
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* # 0x1.47ae147ae147dp-7 0.010000000000000004
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* # 0x1.47ae147ae147ep-7 0.010000000000000005
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* # 0x1.47ae147ae147fp-7 0.010000000000000007
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* # 0x1.47ae147ae148p-7 0.010000000000000009
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* # 0x1.47ae147ae1481p-7 0.01000000000000001
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* # 0x1.47ae147ae1482p-7 0.010000000000000012
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* # 0x1.47ae147ae1483p-7 0.010000000000000014
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* # 0x1.47ae147ae1484p-7 0.010000000000000016
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* # 0x1.47ae147ae1485p-7 0.010000000000000018
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* # 0x1.47ae147ae1486p-7 0.01000000000000002
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* # 0x1.47ae147ae1487p-7 0.010000000000000021
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* # 0x1.47ae147ae1488p-7 0.010000000000000023
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* # 0x1.47ae147ae1489p-7 0.010000000000000024
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* # 0x1.47ae147ae148ap-7 0.010000000000000026
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* # 0x1.47ae147ae148bp-7 0.010000000000000028
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* # 0x1.47ae147ae148cp-7 0.01000000000000003
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* # 0x1.47ae147ae148dp-7 0.010000000000000031
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* # 0x1.47ae147ae148ep-7 0.010000000000000033
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*
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* f = 0.0
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* 100.times { f += 0.1 }
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* p f #=> 9.99999999999998 # should be 10.0 in the ideal world.
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* p 10-f #=> 1.9539925233402755e-14 # the floating-point error.
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* p(10.0.next_float-10) #=> 1.7763568394002505e-15 # 1 ulp (units in the last place).
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* p((10-f)/(10.0.next_float-10)) #=> 11.0 # the error is 11 ulp.
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* p((10-f)/(10*Float::EPSILON)) #=> 8.8 # approximation of the above.
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* p "%a" % f #=> "0x1.3fffffffffff5p+3" # the last hex digit is 5. 16 - 5 = 11 ulp.
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*
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*/
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static VALUE
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flo_next_float(VALUE vx)
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{
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double x, y;
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x = NUM2DBL(vx);
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y = nextafter(x, INFINITY);
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return DBL2NUM(y);
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}
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/*
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* call-seq:
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* float.prev_float -> float
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*
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* Returns the previous representable floatint-point number.
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*
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* (-Float::MAX).prev_float and (-Float::INFINITY).prev_float is -Float::INFINITY.
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*
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* Float::NAN.prev_float is Float::NAN.
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*
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* For example:
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*
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* p 0.01.prev_float #=> 0.009999999999999998
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* p 1.0.prev_float #=> 0.9999999999999999
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* p 100.0.prev_float #=> 99.99999999999999
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*
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* p 0.01 - 0.01.prev_float #=> 1.734723475976807e-18
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* p 1.0 - 1.0.prev_float #=> 1.1102230246251565e-16
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* p 100.0 - 100.0.prev_float #=> 1.4210854715202004e-14
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*
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* f = 0.01; 20.times { printf "%-20a %s\n", f, f.to_s; f = f.prev_float }
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* #=> 0x1.47ae147ae147bp-7 0.01
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* # 0x1.47ae147ae147ap-7 0.009999999999999998
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* # 0x1.47ae147ae1479p-7 0.009999999999999997
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* # 0x1.47ae147ae1478p-7 0.009999999999999995
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* # 0x1.47ae147ae1477p-7 0.009999999999999993
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* # 0x1.47ae147ae1476p-7 0.009999999999999992
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* # 0x1.47ae147ae1475p-7 0.00999999999999999
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* # 0x1.47ae147ae1474p-7 0.009999999999999988
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* # 0x1.47ae147ae1473p-7 0.009999999999999986
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* # 0x1.47ae147ae1472p-7 0.009999999999999985
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* # 0x1.47ae147ae1471p-7 0.009999999999999983
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* # 0x1.47ae147ae147p-7 0.009999999999999981
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* # 0x1.47ae147ae146fp-7 0.00999999999999998
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* # 0x1.47ae147ae146ep-7 0.009999999999999978
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* # 0x1.47ae147ae146dp-7 0.009999999999999976
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* # 0x1.47ae147ae146cp-7 0.009999999999999974
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* # 0x1.47ae147ae146bp-7 0.009999999999999972
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* # 0x1.47ae147ae146ap-7 0.00999999999999997
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* # 0x1.47ae147ae1469p-7 0.009999999999999969
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* # 0x1.47ae147ae1468p-7 0.009999999999999967
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*
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*/
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static VALUE
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flo_prev_float(VALUE vx)
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{
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double x, y;
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x = NUM2DBL(vx);
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y = nextafter(x, -INFINITY);
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return DBL2NUM(y);
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}
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/*
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* call-seq:
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* float.floor -> integer
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|
@ -4106,6 +4219,8 @@ Init_Numeric(void)
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rb_define_method(rb_cFloat, "nan?", flo_is_nan_p, 0);
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rb_define_method(rb_cFloat, "infinite?", flo_is_infinite_p, 0);
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rb_define_method(rb_cFloat, "finite?", flo_is_finite_p, 0);
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rb_define_method(rb_cFloat, "next_float", flo_next_float, 0);
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rb_define_method(rb_cFloat, "prev_float", flo_prev_float, 0);
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sym_to = ID2SYM(rb_intern("to"));
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sym_by = ID2SYM(rb_intern("by"));
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|
|
|
@ -0,0 +1,57 @@
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require 'test/unit'
|
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require "-test-/float"
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|
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class TestFloatExt < Test::Unit::TestCase
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NEXTAFTER_VALUES = [
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-Float::INFINITY,
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-Float::MAX,
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-100.0,
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-1.0-Float::EPSILON,
|
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-1.0,
|
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-Float::EPSILON,
|
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-Float::MIN/2,
|
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-Math.ldexp(0.5, Float::MIN_EXP - Float::MANT_DIG + 1),
|
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-0.0,
|
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0.0,
|
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Math.ldexp(0.5, Float::MIN_EXP - Float::MANT_DIG + 1),
|
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Float::MIN/2,
|
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Float::MIN,
|
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Float::EPSILON,
|
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1.0,
|
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1.0+Float::EPSILON,
|
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100.0,
|
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Float::MAX,
|
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Float::INFINITY,
|
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Float::NAN
|
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]
|
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|
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test_number = 0
|
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NEXTAFTER_VALUES.each {|n1|
|
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NEXTAFTER_VALUES.each {|n2|
|
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tag = n2.infinite? ? "ruby" : "other"
|
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test_name = "test_nextafter_#{test_number}_#{tag}_#{n1}_#{n2}"
|
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test_number += 1
|
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define_method(test_name) {
|
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v1 = Bug::Float.missing_nextafter(n1, n2)
|
||||
v2 = Bug::Float.system_nextafter(n1, n2)
|
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assert_kind_of(Float, v1)
|
||||
assert_kind_of(Float, v2)
|
||||
if v1.nan?
|
||||
assert(v2.nan?, "Bug::Float.system_nextafter(#{n1}, #{n2}).nan?")
|
||||
else
|
||||
assert_equal(v1, v2,
|
||||
"Bug::Float.missing_nextafter(#{'%a' % n1}, #{'%a' % n2}) = #{'%a' % v1} != " +
|
||||
"#{'%a' % v2} = Bug::Float.system_nextafter(#{'%a' % n1}, #{'%a' % n2})")
|
||||
if v1 == 0
|
||||
s1 = 1.0/v1 < 0 ? "negative-zero" : "positive-zero"
|
||||
s2 = 1.0/v2 < 0 ? "negative-zero" : "positive-zero"
|
||||
assert_equal(s1, s2,
|
||||
"Bug::Float.missing_nextafter(#{'%a' % n1}, #{'%a' % n2}) = #{'%a' % v1} != " +
|
||||
"#{'%a' % v2} = Bug::Float.system_nextafter(#{'%a' % n1}, #{'%a' % n2})")
|
||||
end
|
||||
end
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
end
|
|
@ -619,4 +619,39 @@ class TestFloat < Test::Unit::TestCase
|
|||
assert_in_epsilon(10.0, ("1."+"1"*300000).to_f*9)
|
||||
end;
|
||||
end
|
||||
|
||||
def test_next_float
|
||||
smallest = 0.0.next_float
|
||||
assert_equal(-Float::MAX, (-Float::INFINITY).next_float)
|
||||
assert_operator(-Float::MAX, :<, (-Float::MAX).next_float)
|
||||
assert_equal(Float::EPSILON/2, (-1.0).next_float + 1.0)
|
||||
assert_operator(0.0, :<, smallest)
|
||||
assert_operator([0.0, smallest], :include?, smallest/2)
|
||||
assert_equal(Float::EPSILON, 1.0.next_float - 1.0)
|
||||
assert_equal(Float::INFINITY, Float::MAX.next_float)
|
||||
assert_equal(Float::INFINITY, Float::INFINITY.next_float)
|
||||
assert(Float::NAN.next_float.nan?)
|
||||
end
|
||||
|
||||
def test_prev_float
|
||||
smallest = 0.0.next_float
|
||||
assert_equal(-Float::INFINITY, (-Float::INFINITY).prev_float)
|
||||
assert_equal(-Float::INFINITY, (-Float::MAX).prev_float)
|
||||
assert_equal(-Float::EPSILON, (-1.0).prev_float + 1.0)
|
||||
assert_equal(-smallest, 0.0.prev_float)
|
||||
assert_operator([0.0, 0.0.prev_float], :include?, 0.0.prev_float/2)
|
||||
assert_equal(-Float::EPSILON/2, 1.0.prev_float - 1.0)
|
||||
assert_operator(Float::MAX, :>, Float::MAX.prev_float)
|
||||
assert_equal(Float::MAX, Float::INFINITY.prev_float)
|
||||
assert(Float::NAN.prev_float.nan?)
|
||||
end
|
||||
|
||||
def test_next_prev_float_zero
|
||||
z = 0.0.next_float.prev_float
|
||||
assert_equal(0.0, z)
|
||||
assert_equal(Float::INFINITY, 1.0/z)
|
||||
z = 0.0.prev_float.next_float
|
||||
assert_equal(0.0, z)
|
||||
assert_equal(-Float::INFINITY, 1.0/z)
|
||||
end
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end
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Загрузка…
Ссылка в новой задаче