For an m-by-n matrix A with m >= n, the LU decomposition is an m-by-n unit lower triangular matrix L, an n-by-n upper triangular matrix U, and a m-by-m permutation matrix P so that L*U = P*A. If m < n, then L is m-by-m and U is m-by-n.
The LUP decomposition with pivoting always exists, even if the matrix is singular, so the constructor will never fail. The primary use of the LU decomposition is in the solution of square systems of simultaneous linear equations. This will fail if singular? returns true.
Command is not supported on server.
Gem::ConfigFile
RubyGems options and gem command options from gemrc.
gemrc is a YAML file that uses strings to match gem command arguments and symbols to match RubyGems options.
Gem command arguments use a String
key that matches the command name and allow you to specify default arguments:
install: --no-rdoc --no-ri update: --no-rdoc --no-ri
You can use gem:
to set default arguments for all commands.
RubyGems options use symbol keys. Valid options are:
:backtrace
See backtrace
:sources
Sets Gem::sources
:verbose
See verbose
:concurrent_downloads
gemrc files may exist in various locations and are read and merged in the following order:
system wide (/etc/gemrc)
per user (~/.gemrc)
per environment (gemrc files listed in the GEMRC environment variable)
Installs a gem along with all its dependencies from local and remote gems.
Raised when there are conflicting gem specs loaded
Raised when removing a gem with the uninstall command fails
Potentially raised when a specification is validated.
The installer installs the files contained in the .gem into the Gem.home.
Gem::Installer
does the work of putting files in all the right places on the filesystem including unpacking the gem into its gem dir, installing the gemspec in the specifications dir, storing the cached gem in the cache dir, and installing either wrappers or symlinks for executables.
The installer invokes pre and post install hooks. Hooks can be added either through a rubygems_plugin.rb file in an installed gem or via a rubygems/defaults/#{RUBY_ENGINE}.rb or rubygems/defaults/operating_system.rb file. See Gem.pre_install
and Gem.post_install
for details.
Gem::StubSpecification
reads the stub: line from the gemspec. This prevents us having to eval the entire gemspec in order to find out certain information.
An Uninstaller
.
The uninstaller fires pre and post uninstall hooks. Hooks can be added either through a rubygems_plugin.rb file in an installed gem or via a rubygems/defaults/#{RUBY_ENGINE}.rb or rubygems/defaults/operating_system.rb file. See Gem.pre_uninstall
and Gem.post_uninstall
for details.
Not a URI
component.
Client sent TCP reset (RST) before server has accepted the connection requested by client.
This module provides instance methods for a digest implementation object to calculate message digest values.
This module contains configuration information about the SSL
extension, for example if socket support is enabled, or the host name TLS extension is enabled. Constants in this module will always be defined, but contain true
or false
values depending on the configuration of your OpenSSL
installation.
Mixin module that provides the following:
Access to the CGI
environment variables as methods. See documentation to the CGI
class for a list of these variables. The methods are exposed by removing the leading HTTP_
(if it exists) and downcasing the name. For example, auth_type
will return the environment variable AUTH_TYPE
, and accept
will return the value for HTTP_ACCEPT
.
Access to cookies, including the cookies attribute.
Access to parameters, including the params attribute, and overloading []
to perform parameter value lookup by key.
The initialize_query
method, for initializing the above mechanisms, handling multipart forms, and allowing the class to be used in “offline” mode.
Mixin module providing HTML generation methods.
For example,
cgi.a("http://www.example.com") { "Example" } # => "<A HREF=\"http://www.example.com\">Example</A>"
Modules Html3, Html4, etc., contain more basic HTML-generation methods (#title
, #h1
, etc.).
See class CGI
for a detailed example.