The Matrix class represents a mathematical matrix. It provides methods for creating matrices, operating on them arithmetically and algebraically, and determining their mathematical properties such as trace, rank, inverse, determinant, or eigensystem.

Raised when attempting to convert special float values (in particular Infinity or NaN) to numerical classes which don’t support them.

Float::INFINITY.to_r   #=> FloatDomainError: Infinity

Provides mathematical functions.

Example:

require "bigdecimal/math"

include BigMath

a = BigDecimal((PI(100)/2).to_s)
puts sin(a,100) # => 0.99999999999999999999......e0

The Benchmark module provides methods to measure and report the time used to execute Ruby code.

• Measure the time to construct the string given by the expression "a"*1_000_000_000:

  require 'benchmark'
  
  puts Benchmark.measure { "a"*1_000_000_000 }
  

  On my machine (OSX 10.8.3 on i5 1.7 GHz) this generates:

  0.350000   0.400000   0.750000 (  0.835234)

  This report shows the user CPU time, system CPU time, the sum of the user and system CPU times, and the elapsed real time. The unit of time is seconds.

• Do some experiments sequentially using the bm method:

  require 'benchmark'
  
  n = 5000000
  Benchmark.bm do |x|
    x.report { for i in 1..n; a = "1"; end }
    x.report { n.times do   ; a = "1"; end }
    x.report { 1.upto(n) do ; a = "1"; end }
  end
  

  The result:

      user     system      total        real
  1.010000   0.000000   1.010000 (  1.014479)
  1.000000   0.000000   1.000000 (  0.998261)
  0.980000   0.000000   0.980000 (  0.981335)

• Continuing the previous example, put a label in each report:

  require 'benchmark'
  
  n = 5000000
  Benchmark.bm(7) do |x|
    x.report("for:")   { for i in 1..n; a = "1"; end }
    x.report("times:") { n.times do   ; a = "1"; end }
    x.report("upto:")  { 1.upto(n) do ; a = "1"; end }
  end
  

The result:

              user     system      total        real
for:      1.010000   0.000000   1.010000 (  1.015688)
times:    1.000000   0.000000   1.000000 (  1.003611)
upto:     1.030000   0.000000   1.030000 (  1.028098)

• The times for some benchmarks depend on the order in which items are run. These differences are due to the cost of memory allocation and garbage collection. To avoid these discrepancies, the bmbm method is provided. For example, to compare ways to sort an array of floats:

  require 'benchmark'
  
  array = (1..1000000).map { rand }
  
  Benchmark.bmbm do |x|
    x.report("sort!") { array.dup.sort! }
    x.report("sort")  { array.dup.sort  }
  end
  

  The result:

  Rehearsal -----------------------------------------
  sort!   1.490000   0.010000   1.500000 (  1.490520)
  sort    1.460000   0.000000   1.460000 (  1.463025)
  -------------------------------- total: 2.960000sec
  
              user     system      total        real
  sort!   1.460000   0.000000   1.460000 (  1.460465)
  sort    1.450000   0.010000   1.460000 (  1.448327)

• Report statistics of sequential experiments with unique labels, using the benchmark method:

  require 'benchmark'
  include Benchmark         # we need the CAPTION and FORMAT constants
  
  n = 5000000
  Benchmark.benchmark(CAPTION, 7, FORMAT, ">total:", ">avg:") do |x|
    tf = x.report("for:")   { for i in 1..n; a = "1"; end }
    tt = x.report("times:") { n.times do   ; a = "1"; end }
    tu = x.report("upto:")  { 1.upto(n) do ; a = "1"; end }
    [tf+tt+tu, (tf+tt+tu)/3]
  end
  

  The result:

               user     system      total        real
  for:      0.950000   0.000000   0.950000 (  0.952039)
  times:    0.980000   0.000000   0.980000 (  0.984938)
  upto:     0.950000   0.000000   0.950000 (  0.946787)
  >total:   2.880000   0.000000   2.880000 (  2.883764)
  >avg:     0.960000   0.000000   0.960000 (  0.961255)

Trigonometric and transcendental functions for complex numbers.

CMath is a library that provides trigonometric and transcendental functions for complex numbers. The functions in this module accept integers, floating-point numbers or complex numbers as arguments.

Note that the selection of functions is similar, but not identical, to that in module math. The reason for having two modules is that some users aren’t interested in complex numbers, and perhaps don’t even know what they are. They would rather have Math.sqrt(-1) raise an exception than return a complex number.

For more information you can see Complex class.

Usage

To start using this library, simply require cmath library:

require "cmath"

mkmf.rb is used by Ruby C extensions to generate a Makefile which will correctly compile and link the C extension to Ruby and a third-party library.

The Math module contains module functions for basic trigonometric and transcendental functions. See class Float for a list of constants that define Ruby’s floating point accuracy.

Domains and codomains are given only for real (not complex) numbers.

Generated when trying to lookup a gem to indicate that the gem was found, but that it isn’t usable on the current platform.

fetch and install read these and report them to the user to aid in figuring out why a gem couldn’t be installed.

Raised when a gem dependencies file specifies a ruby version that does not match the current version.

Default formatter for log messages.

Individual switch class. Not important to the user.

Defined within Switch are several Switch-derived classes: NoArgument, RequiredArgument, etc.

An implementation of PseudoPrimeGenerator.

Uses EratosthenesSieve.

The command manager registers and installs all the individual sub-commands supported by the gem command.

Extra commands can be provided by writing a rubygems_plugin.rb file in an installed gem. You should register your command against the Gem::CommandManager instance, like this:

# file rubygems_plugin.rb
require 'rubygems/command_manager'

Gem::CommandManager.instance.register_command :edit

You should put the implementation of your command in rubygems/commands.

# file rubygems/commands/edit_command.rb
class Gem::Commands::EditCommand < Gem::Command
  # ...
end

See Gem::Command for instructions on writing gem commands.

An error that indicates we weren’t able to fetch some data from a source

Used to raise parsing and loading errors

RemoteFetcher handles the details of fetching gems and gem information from a remote source.

SpecFetcher handles metadata updates from remote gem repositories.

A fake Gem::RemoteFetcher for use in tests or to avoid real live HTTP requests when testing code that uses RubyGems.

Example:

@fetcher = Gem::FakeFetcher.new
@fetcher.data['http://gems.example.com/yaml'] = source_index.to_yaml
Gem::RemoteFetcher.fetcher = @fetcher

# invoke RubyGems code

paths = @fetcher.paths
assert_equal 'http://gems.example.com/yaml', paths.shift
assert paths.empty?, paths.join(', ')

See RubyGems’ tests for more examples of FakeFetcher.

The UriFormatter handles URIs from user-input and escaping.

uf = Gem::UriFormatter.new 'example.com'

p uf.normalize #=> 'http://example.com'