spec/frozen/1.8/library/mathn/rational/power2_spec.rb

   1 require File.dirname(__FILE__) + '/../../../spec_helper'
   2 require 'mathn'
   3
   4 describe "Rational#power2 when passed [Rational]" do
   5   ruby_bug "#175", "1.8.7" do
   6     it "returns Rational.new!(1, 1) when the passed argument is 0" do
   7       (Rational.new!(3, 4).power2(Rational.new!(0, 3))).should == Rational.new!(1, 1)
   8       (Rational.new!(-3, 4).power2(Rational.new!(0, 3))).should == Rational.new!(1, 1)
   9       (Rational.new!(3, -4).power2(Rational.new!(0, 3))).should == Rational.new!(1, 1)
  10       (Rational.new!(3, 4).power2(Rational.new!(0, -3))).should == Rational.new!(1, 1)
  11     end
  12   end
  13
  14   it "returns Rational.new!(1, 1) when self is 1" do
  15     (Rational.new!(1,1).power2(Rational.new!(2, 3))).should == Rational.new!(1, 1)
  16     (Rational.new!(1,1).power2(Rational.new!(-2, 3))).should == Rational.new!(1, 1)
  17     (Rational.new!(1,1).power2(Rational.new!(2, -3))).should == Rational.new!(1, 1)
  18     (Rational.new!(1,1).power2(Rational.new!(-2, -3))).should == Rational.new!(1, 1)
  19   end
  20
  21   it "returns Rational.new!(0, 1) when self is 0" do
  22     (Rational.new!(0,1).power2(Rational.new!(2, 3))).should == Rational.new!(0, 1)
  23     (Rational.new!(0,1).power2(Rational.new!(-2, 3))).should == Rational.new!(0, 1)
  24     (Rational.new!(0,1).power2(Rational.new!(2, -3))).should == Rational.new!(0, 1)
  25     (Rational.new!(0,1).power2(Rational.new!(-2, -3))).should == Rational.new!(0, 1)
  26   end
  27
  28   ruby_bug "#175", "1.8.7" do
  29     it "returns the Rational value of self raised to the passed argument" do
  30       (Rational.new!(1, 4).power2(Rational.new!(1, 2))).should == Rational.new!(1, 2)
  31       (Rational.new!(1, 4).power2(Rational.new!(1, -2))).should == Rational.new!(2, 1)
  32     end
  33   end
  34
  35   it "returns a Complex number when self is negative" do
  36     (Rational.new!(-1,2).power2(Rational.new!(2, 3))).should be_close(Complex(-0.314980262473718, 0.545561817985861), TOLERANCE)
  37     (Rational.new!(-1,2).power2(Rational.new!(-2, 3))).should be_close(Complex(-0.793700525984099, -1.3747296369986), TOLERANCE)
  38     (Rational.new!(-1,2).power2(Rational.new!(2, -3))).should be_close(Complex(-0.793700525984099, -1.3747296369986), TOLERANCE)
  39   end
  40 end
  41
  42 describe "Rational#power2 when passed [Integer]" do
  43   it "returns the Rational value of self raised to the passed argument" do
  44     (Rational.new!(3, 4).power2(4)).should == Rational.new!(81, 256)
  45     (Rational.new!(3, 4).power2(-4)).should == Rational.new!(256, 81)
  46     (Rational.new!(-3, 4).power2(-4)).should == Rational.new!(256, 81)
  47     (Rational.new!(3, -4).power2(-4)).should == Rational.new!(256, 81)
  48   end
  49
  50   it "returns Rational.new!(1, 1) when the passed argument is 0" do
  51     (Rational.new!(3, 4).power2(0)).should == Rational.new!(1, 1)
  52     (Rational.new!(-3, 4).power2(0)).should == Rational.new!(1, 1)
  53     (Rational.new!(3, -4).power2(0)).should == Rational.new!(1, 1)
  54
  55     (Rational.new!(bignum_value, 100).power2(0)).should == Rational.new!(1, 1)
  56     (Rational.new!(3, -bignum_value).power2(0)).should == Rational.new!(1, 1)
  57   end
  58 end
  59
  60 describe "Rational#power2 when passed [Float]" do
  61   it "returns self converted to Float and raised to the passed argument" do
  62     (Rational.new!(3, 2).power2(3.0)).should == 3.375
  63     (Rational.new!(3, 2).power2(1.5)).should be_close(1.83711730708738, TOLERANCE)
  64     (Rational.new!(3, 2).power2(-1.5)).should be_close(0.544331053951817, TOLERANCE)
  65   end
  66
  67   it "returns 1.0 when the passed argument is 0" do
  68     (Rational.new!(3, 4).power2(0.0)).should == 1.0
  69     (Rational.new!(-3, 4).power2(0.0)).should == 1.0
  70     (Rational.new!(-3, 4).power2(0.0)).should == 1.0
  71   end
  72
  73   it "returns NaN if self is negative and the passed argument is not 0" do
  74     (Rational.new!(-3, 2).power2(1.5)).nan?.should be_true
  75     (Rational.new!(3, -2).power2(1.5)).nan?.should be_true
  76     (Rational.new!(3, -2).power2(-1.5)).nan?.should be_true
  77   end
  78 end