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author | nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2018-06-17 02:37:32 +0000 |
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committer | nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2018-06-17 02:37:32 +0000 |
commit | 4fedad85efa84f25cad199eb325d3a300778a046 (patch) | |
tree | 98e8c59f05a3a61e4e271d2e1ab100494a59b954 /complex.c | |
parent | 90d065530784a110681ccef1326d63eac9cdc469 (diff) | |
download | ruby-4fedad85efa84f25cad199eb325d3a300778a046.tar.gz |
refine Integer#** and Float#**
* complex.c (rb_dbl_complex_polar): utility function, which
returns more precise value in right angle cases.
* bignum.c (rb_big_pow): use rb_dbl_complex_polar().
* numeric.c (rb_float_pow, fix_pow): create a Complex by polar
form.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63678 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'complex.c')
-rw-r--r-- | complex.c | 22 |
1 files changed, 22 insertions, 0 deletions
@@ -540,6 +540,28 @@ f_complex_polar(VALUE klass, VALUE x, VALUE y) f_mul(x, m_sin(y))); } +/* returns a Complex or Float of ang*PI-rotated abs */ +VALUE +rb_dbl_complex_polar(double abs, double ang) +{ + double fi; + const double fr = modf(ang, &fi); + int pos = fr == +0.5; + + if (pos || fr == -0.5) { + if ((modf(fi / 2.0, &fi) != fr) ^ pos) abs = -abs; + return rb_complex_new(RFLOAT_0, DBL2NUM(abs)); + } + else if (fr == 0.0) { + if (modf(fi / 2.0, &fi) != 0.0) abs = -abs; + return DBL2NUM(abs); + } + else { + ang *= M_PI; + return rb_complex_new(DBL2NUM(abs * cos(ang)), DBL2NUM(abs * sin(ang))); + } +} + /* * call-seq: * Complex.polar(abs[, arg]) -> complex |