зеркало из https://github.com/github/ruby.git
1273 строки
27 KiB
Ruby
1273 строки
27 KiB
Ruby
#!/usr/local/bin/ruby
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#--
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# matrix.rb -
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# $Release Version: 1.0$
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# $Revision: 1.11 $
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# $Date: 1999/10/06 11:01:53 $
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# Original Version from Smalltalk-80 version
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# on July 23, 1985 at 8:37:17 am
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# by Keiju ISHITSUKA
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#++
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#
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# = matrix.rb
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#
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# An implementation of Matrix and Vector classes.
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#
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# Author:: Keiju ISHITSUKA
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# Documentation:: Gavin Sinclair (sourced from <i>Ruby in a Nutshell</i> (Matsumoto, O'Reilly))
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#
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# See classes Matrix and Vector for documentation.
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#
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require "e2mmap.rb"
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module ExceptionForMatrix # :nodoc:
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extend Exception2MessageMapper
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def_e2message(TypeError, "wrong argument type %s (expected %s)")
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def_e2message(ArgumentError, "Wrong # of arguments(%d for %d)")
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def_exception("ErrDimensionMismatch", "\#{self.name} dimension mismatch")
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def_exception("ErrNotRegular", "Not Regular Matrix")
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def_exception("ErrOperationNotDefined", "This operation(%s) can\\'t defined")
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end
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#
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# The +Matrix+ class represents a mathematical matrix, and provides methods for creating
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# special-case matrices (zero, identity, diagonal, singular, vector), operating on them
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# arithmetically and algebraically, and determining their mathematical properties (trace, rank,
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# inverse, determinant).
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#
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# Note that although matrices should theoretically be rectangular, this is not
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# enforced by the class.
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#
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# Also note that the determinant of integer matrices may be incorrectly calculated unless you
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# also <tt>require 'mathn'</tt>. This may be fixed in the future.
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#
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# == Method Catalogue
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#
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# To create a matrix:
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# * <tt> Matrix[*rows] </tt>
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# * <tt> Matrix.[](*rows) </tt>
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# * <tt> Matrix.rows(rows, copy = true) </tt>
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# * <tt> Matrix.columns(columns) </tt>
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# * <tt> Matrix.diagonal(*values) </tt>
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# * <tt> Matrix.scalar(n, value) </tt>
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# * <tt> Matrix.scalar(n, value) </tt>
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# * <tt> Matrix.identity(n) </tt>
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# * <tt> Matrix.unit(n) </tt>
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# * <tt> Matrix.I(n) </tt>
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# * <tt> Matrix.zero(n) </tt>
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# * <tt> Matrix.row_vector(row) </tt>
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# * <tt> Matrix.column_vector(column) </tt>
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#
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# To access Matrix elements/columns/rows/submatrices/properties:
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# * <tt> [](i, j) </tt>
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# * <tt> #row_size </tt>
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# * <tt> #column_size </tt>
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# * <tt> #row(i) </tt>
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# * <tt> #column(j) </tt>
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# * <tt> #collect </tt>
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# * <tt> #map </tt>
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# * <tt> #minor(*param) </tt>
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#
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# Properties of a matrix:
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# * <tt> #regular? </tt>
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# * <tt> #singular? </tt>
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# * <tt> #square? </tt>
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#
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# Matrix arithmetic:
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# * <tt> *(m) </tt>
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# * <tt> +(m) </tt>
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# * <tt> -(m) </tt>
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# * <tt> #/(m) </tt>
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# * <tt> #inverse </tt>
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# * <tt> #inv </tt>
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# * <tt> ** </tt>
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#
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# Matrix functions:
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# * <tt> #determinant </tt>
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# * <tt> #det </tt>
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# * <tt> #rank </tt>
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# * <tt> #trace </tt>
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# * <tt> #tr </tt>
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# * <tt> #transpose </tt>
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# * <tt> #t </tt>
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#
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# Conversion to other data types:
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# * <tt> #coerce(other) </tt>
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# * <tt> #row_vectors </tt>
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# * <tt> #column_vectors </tt>
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# * <tt> #to_a </tt>
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#
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# String representations:
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# * <tt> #to_s </tt>
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# * <tt> #inspect </tt>
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#
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class Matrix
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@RCS_ID='-$Id: matrix.rb,v 1.11 1999/10/06 11:01:53 keiju Exp keiju $-'
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# extend Exception2MessageMapper
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include ExceptionForMatrix
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# instance creations
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private_class_method :new
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#
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# Creates a matrix where each argument is a row.
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# Matrix[ [25, 93], [-1, 66] ]
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# => 25 93
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# -1 66
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#
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def Matrix.[](*rows)
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new(:init_rows, rows, false)
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end
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#
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# Creates a matrix where +rows+ is an array of arrays, each of which is a row
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# to the matrix. If the optional argument +copy+ is false, use the given
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# arrays as the internal structure of the matrix without copying.
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# Matrix.rows([[25, 93], [-1, 66]])
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# => 25 93
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# -1 66
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def Matrix.rows(rows, copy = true)
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new(:init_rows, rows, copy)
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end
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#
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# Creates a matrix using +columns+ as an array of column vectors.
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# Matrix.columns([[25, 93], [-1, 66]])
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# => 25 -1
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# 93 66
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#
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#
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def Matrix.columns(columns)
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rows = (0 .. columns[0].size - 1).collect {
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|i|
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(0 .. columns.size - 1).collect {
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|j|
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columns[j][i]
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}
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}
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Matrix.rows(rows, false)
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end
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#
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# Creates a matrix where the diagonal elements are composed of +values+.
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# Matrix.diagonal(9, 5, -3)
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# => 9 0 0
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# 0 5 0
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# 0 0 -3
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#
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def Matrix.diagonal(*values)
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size = values.size
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rows = (0 .. size - 1).collect {
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|j|
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row = Array.new(size).fill(0, 0, size)
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row[j] = values[j]
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row
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}
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rows(rows, false)
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end
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#
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# Creates an +n+ by +n+ diagonal matrix where each diagonal element is
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# +value+.
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# Matrix.scalar(2, 5)
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# => 5 0
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# 0 5
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#
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def Matrix.scalar(n, value)
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Matrix.diagonal(*Array.new(n).fill(value, 0, n))
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end
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#
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# Creates an +n+ by +n+ identity matrix.
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# Matrix.identity(2)
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# => 1 0
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# 0 1
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#
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def Matrix.identity(n)
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Matrix.scalar(n, 1)
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end
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class << Matrix
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alias unit identity
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alias I identity
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end
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#
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# Creates an +n+ by +n+ zero matrix.
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# Matrix.zero(2)
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# => 0 0
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# 0 0
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#
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def Matrix.zero(n)
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Matrix.scalar(n, 0)
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end
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#
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# Creates a single-row matrix where the values of that row are as given in
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# +row+.
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# Matrix.row_vector([4,5,6])
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# => 4 5 6
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#
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def Matrix.row_vector(row)
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case row
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when Vector
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Matrix.rows([row.to_a], false)
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when Array
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Matrix.rows([row.dup], false)
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else
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Matrix.rows([[row]], false)
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end
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end
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#
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# Creates a single-column matrix where the values of that column are as given
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# in +column+.
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# Matrix.column_vector([4,5,6])
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# => 4
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# 5
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# 6
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#
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def Matrix.column_vector(column)
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case column
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when Vector
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Matrix.columns([column.to_a])
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when Array
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Matrix.columns([column])
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else
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Matrix.columns([[column]])
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end
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end
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#
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# This method is used by the other methods that create matrices, and is of no
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# use to general users.
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#
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def initialize(init_method, *argv)
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self.funcall(init_method, *argv)
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end
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def init_rows(rows, copy)
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if copy
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@rows = rows.collect{|row| row.dup}
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else
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@rows = rows
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end
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self
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end
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private :init_rows
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#
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# Returns element (+i+,+j+) of the matrix. That is: row +i+, column +j+.
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#
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def [](i, j)
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@rows[i][j]
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end
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#
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# Returns the number of rows.
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#
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def row_size
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@rows.size
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end
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#
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# Returns the number of columns. Note that it is possible to construct a
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# matrix with uneven columns (e.g. Matrix[ [1,2,3], [4,5] ]), but this is
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# mathematically unsound. This method uses the first row to determine the
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# result.
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#
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def column_size
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@rows[0].size
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end
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#
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# Returns row vector number +i+ of the matrix as a Vector (starting at 0 like
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# an array). When a block is given, the elements of that vector are iterated.
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#
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def row(i) # :yield: e
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if block_given?
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for e in @rows[i]
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yield e
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end
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else
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Vector.elements(@rows[i])
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end
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end
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#
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# Returns column vector number +j+ of the matrix as a Vector (starting at 0
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# like an array). When a block is given, the elements of that vector are
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# iterated.
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#
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def column(j) # :yield: e
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if block_given?
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0.upto(row_size - 1) do
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|i|
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yield @rows[i][j]
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end
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else
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col = (0 .. row_size - 1).collect {
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|i|
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@rows[i][j]
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}
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Vector.elements(col, false)
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end
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end
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#
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# Returns a matrix that is the result of iteration of the given block over all
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# elements of the matrix.
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# Matrix[ [1,2], [3,4] ].collect { |i| i**2 }
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# => 1 4
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# 9 16
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#
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def collect # :yield: e
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rows = @rows.collect{|row| row.collect{|e| yield e}}
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Matrix.rows(rows, false)
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end
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alias map collect
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#
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# Returns a section of the matrix. The parameters are either:
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# * start_row, nrows, start_col, ncols; OR
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# * col_range, row_range
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#
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# Matrix.diagonal(9, 5, -3).minor(0..1, 0..2)
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# => 9 0 0
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# 0 5 0
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#
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def minor(*param)
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case param.size
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when 2
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from_row = param[0].first
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size_row = param[0].end - from_row
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size_row += 1 unless param[0].exclude_end?
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from_col = param[1].first
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size_col = param[1].end - from_col
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size_col += 1 unless param[1].exclude_end?
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when 4
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from_row = param[0]
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size_row = param[1]
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from_col = param[2]
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size_col = param[3]
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else
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Matrix.Raise ArgumentError, param.inspect
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end
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rows = @rows[from_row, size_row].collect{
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|row|
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row[from_col, size_col]
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}
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Matrix.rows(rows, false)
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end
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#--
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# TESTING -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
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#++
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#
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# Returns +true+ if this is a regular matrix.
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#
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def regular?
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square? and rank == column_size
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end
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#
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# Returns +true+ is this is a singular (i.e. non-regular) matrix.
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#
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def singular?
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not regular?
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end
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#
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# Returns +true+ is this is a square matrix. See note in column_size about this
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# being unreliable, though.
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#
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def square?
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column_size == row_size
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end
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#--
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# OBJECT METHODS -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
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#++
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#
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# Returns +true+ if and only if the two matrices contain equal elements.
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#
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def ==(other)
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return false unless Matrix === other
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other.compare_by_row_vectors(@rows)
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end
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alias eql? ==
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#
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# Not really intended for general consumption.
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#
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def compare_by_row_vectors(rows)
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return false unless @rows.size == rows.size
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0.upto(@rows.size - 1) do
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|i|
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return false unless @rows[i] == rows[i]
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end
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true
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end
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#
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# Returns a clone of the matrix, so that the contents of each do not reference
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# identical objects.
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#
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def clone
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Matrix.rows(@rows)
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end
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#
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# Returns a hash-code for the matrix.
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#
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def hash
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value = 0
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for row in @rows
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for e in row
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value ^= e.hash
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end
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end
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return value
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end
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#--
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# ARITHMETIC -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
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#++
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#
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# Matrix multiplication.
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# Matrix[[2,4], [6,8]] * Matrix.identity(2)
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# => 2 4
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# 6 8
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#
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def *(m) # m is matrix or vector or number
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case(m)
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when Numeric
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rows = @rows.collect {
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|row|
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row.collect {
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|e|
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e * m
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}
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}
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return Matrix.rows(rows, false)
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when Vector
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m = Matrix.column_vector(m)
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r = self * m
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return r.column(0)
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when Matrix
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Matrix.Raise ErrDimensionMismatch if column_size != m.row_size
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rows = (0 .. row_size - 1).collect {
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|i|
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(0 .. m.column_size - 1).collect {
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|j|
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vij = 0
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0.upto(column_size - 1) do
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|k|
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vij += self[i, k] * m[k, j]
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end
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vij
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}
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}
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return Matrix.rows(rows, false)
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else
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x, y = m.coerce(self)
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return x * y
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end
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end
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#
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# Matrix addition.
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# Matrix.scalar(2,5) + Matrix[[1,0], [-4,7]]
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# => 6 0
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# -4 12
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#
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def +(m)
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case m
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when Numeric
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Matrix.Raise ErrOperationNotDefined, "+"
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when Vector
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m = Matrix.column_vector(m)
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when Matrix
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else
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x, y = m.coerce(self)
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return x + y
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end
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Matrix.Raise ErrDimensionMismatch unless row_size == m.row_size and column_size == m.column_size
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rows = (0 .. row_size - 1).collect {
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|i|
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(0 .. column_size - 1).collect {
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|j|
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self[i, j] + m[i, j]
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}
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}
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Matrix.rows(rows, false)
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end
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#
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# Matrix subtraction.
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# Matrix[[1,5], [4,2]] - Matrix[[9,3], [-4,1]]
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# => -8 2
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# 8 1
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#
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def -(m)
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case m
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when Numeric
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Matrix.Raise ErrOperationNotDefined, "-"
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when Vector
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m = Matrix.column_vector(m)
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when Matrix
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else
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x, y = m.coerce(self)
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return x - y
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end
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Matrix.Raise ErrDimensionMismatch unless row_size == m.row_size and column_size == m.column_size
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rows = (0 .. row_size - 1).collect {
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|i|
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(0 .. column_size - 1).collect {
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|j|
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self[i, j] - m[i, j]
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}
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}
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Matrix.rows(rows, false)
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end
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#
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# Matrix division (multiplication by the inverse).
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# Matrix[[7,6], [3,9]] / Matrix[[2,9], [3,1]]
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# => -7 1
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# -3 -6
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#
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def /(other)
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case other
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when Numeric
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rows = @rows.collect {
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|row|
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row.collect {
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|e|
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e / other
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}
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}
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return Matrix.rows(rows, false)
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when Matrix
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return self * other.inverse
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else
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x, y = other.coerce(self)
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rerurn x / y
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end
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end
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#
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# Returns the inverse of the matrix.
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# Matrix[[1, 2], [2, 1]].inverse
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# => -1 1
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# 0 -1
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#
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def inverse
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Matrix.Raise ErrDimensionMismatch unless square?
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Matrix.I(row_size).inverse_from(self)
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|
end
|
|
alias inv inverse
|
|
|
|
#
|
|
# Not for public consumption?
|
|
#
|
|
def inverse_from(src)
|
|
size = row_size - 1
|
|
a = src.to_a
|
|
|
|
for k in 0..size
|
|
if (akk = a[k][k]) == 0
|
|
i = k
|
|
begin
|
|
Matrix.Raise ErrNotRegular if (i += 1) > size
|
|
end while a[i][k] == 0
|
|
a[i], a[k] = a[k], a[i]
|
|
@rows[i], @rows[k] = @rows[k], @rows[i]
|
|
akk = a[k][k]
|
|
end
|
|
|
|
for i in 0 .. size
|
|
next if i == k
|
|
q = a[i][k].quo(akk)
|
|
a[i][k] = 0
|
|
|
|
(k + 1).upto(size) do
|
|
|j|
|
|
a[i][j] -= a[k][j] * q
|
|
end
|
|
0.upto(size) do
|
|
|j|
|
|
@rows[i][j] -= @rows[k][j] * q
|
|
end
|
|
end
|
|
|
|
(k + 1).upto(size) do
|
|
|j|
|
|
a[k][j] = a[k][j].quo(akk)
|
|
end
|
|
0.upto(size) do
|
|
|j|
|
|
@rows[k][j] = @rows[k][j].quo(akk)
|
|
end
|
|
end
|
|
self
|
|
end
|
|
#alias reciprocal inverse
|
|
|
|
#
|
|
# Matrix exponentiation. Defined for integer powers only. Equivalent to
|
|
# multiplying the matrix by itself N times.
|
|
# Matrix[[7,6], [3,9]] ** 2
|
|
# => 67 96
|
|
# 48 99
|
|
#
|
|
def ** (other)
|
|
if other.kind_of?(Integer)
|
|
x = self
|
|
if other <= 0
|
|
x = self.inverse
|
|
return Matrix.identity(self.column_size) if other == 0
|
|
other = -other
|
|
end
|
|
z = x
|
|
n = other - 1
|
|
while n != 0
|
|
while (div, mod = n.divmod(2)
|
|
mod == 0)
|
|
x = x * x
|
|
n = div
|
|
end
|
|
z *= x
|
|
n -= 1
|
|
end
|
|
z
|
|
elsif other.kind_of?(Float) || defined?(Rational) && other.kind_of?(Rational)
|
|
Matrix.Raise ErrOperationNotDefined, "**"
|
|
else
|
|
Matrix.Raise ErrOperationNotDefined, "**"
|
|
end
|
|
end
|
|
|
|
#--
|
|
# MATRIX FUNCTIONS -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
|
|
#++
|
|
|
|
#
|
|
# Returns the determinant of the matrix. If the matrix is not square, the
|
|
# result is 0.
|
|
# Matrix[[7,6], [3,9]].determinant
|
|
# => 63
|
|
#
|
|
def determinant
|
|
return 0 unless square?
|
|
|
|
size = row_size - 1
|
|
a = to_a
|
|
|
|
det = 1
|
|
k = 0
|
|
begin
|
|
if (akk = a[k][k]) == 0
|
|
i = k
|
|
begin
|
|
return 0 if (i += 1) > size
|
|
end while a[i][k] == 0
|
|
a[i], a[k] = a[k], a[i]
|
|
akk = a[k][k]
|
|
det *= -1
|
|
end
|
|
(k + 1).upto(size) do
|
|
|i|
|
|
q = a[i][k].quo(akk)
|
|
(k + 1).upto(size) do
|
|
|j|
|
|
a[i][j] -= a[k][j] * q
|
|
end
|
|
end
|
|
det *= akk
|
|
end while (k += 1) <= size
|
|
det
|
|
end
|
|
alias det determinant
|
|
|
|
#
|
|
# Returns the rank of the matrix. Beware that using Float values, with their
|
|
# usual lack of precision, can affect the value returned by this method. Use
|
|
# Rational values instead if this is important to you.
|
|
# Matrix[[7,6], [3,9]].rank
|
|
# => 2
|
|
#
|
|
def rank
|
|
if column_size > row_size
|
|
a = transpose.to_a
|
|
a_column_size = row_size
|
|
a_row_size = column_size
|
|
else
|
|
a = to_a
|
|
a_column_size = column_size
|
|
a_row_size = row_size
|
|
end
|
|
rank = 0
|
|
k = 0
|
|
begin
|
|
if (akk = a[k][k]) == 0
|
|
i = k
|
|
exists = true
|
|
begin
|
|
if (i += 1) > a_column_size - 1
|
|
exists = false
|
|
break
|
|
end
|
|
end while a[i][k] == 0
|
|
if exists
|
|
a[i], a[k] = a[k], a[i]
|
|
akk = a[k][k]
|
|
else
|
|
i = k
|
|
exists = true
|
|
begin
|
|
if (i += 1) > a_row_size - 1
|
|
exists = false
|
|
break
|
|
end
|
|
end while a[k][i] == 0
|
|
if exists
|
|
k.upto(a_column_size - 1) do
|
|
|j|
|
|
a[j][k], a[j][i] = a[j][i], a[j][k]
|
|
end
|
|
akk = a[k][k]
|
|
else
|
|
next
|
|
end
|
|
end
|
|
end
|
|
(k + 1).upto(a_row_size - 1) do
|
|
|i|
|
|
q = a[i][k].quo(akk)
|
|
(k + 1).upto(a_column_size - 1) do
|
|
|j|
|
|
a[i][j] -= a[k][j] * q
|
|
end
|
|
end
|
|
rank += 1
|
|
end while (k += 1) <= a_column_size - 1
|
|
return rank
|
|
end
|
|
|
|
#
|
|
# Returns the trace (sum of diagonal elements) of the matrix.
|
|
# Matrix[[7,6], [3,9]].trace
|
|
# => 16
|
|
#
|
|
def trace
|
|
tr = 0
|
|
0.upto(column_size - 1) do
|
|
|i|
|
|
tr += @rows[i][i]
|
|
end
|
|
tr
|
|
end
|
|
alias tr trace
|
|
|
|
#
|
|
# Returns the transpose of the matrix.
|
|
# Matrix[[1,2], [3,4], [5,6]]
|
|
# => 1 2
|
|
# 3 4
|
|
# 5 6
|
|
# Matrix[[1,2], [3,4], [5,6]].transpose
|
|
# => 1 3 5
|
|
# 2 4 6
|
|
#
|
|
def transpose
|
|
Matrix.columns(@rows)
|
|
end
|
|
alias t transpose
|
|
|
|
#--
|
|
# CONVERTING -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
|
|
#++
|
|
|
|
#
|
|
# FIXME: describe #coerce.
|
|
#
|
|
def coerce(other)
|
|
case other
|
|
when Numeric
|
|
return Scalar.new(other), self
|
|
else
|
|
raise TypeError, "#{self.class} can't be coerced into #{other.class}"
|
|
end
|
|
end
|
|
|
|
#
|
|
# Returns an array of the row vectors of the matrix. See Vector.
|
|
#
|
|
def row_vectors
|
|
rows = (0 .. row_size - 1).collect {
|
|
|i|
|
|
row(i)
|
|
}
|
|
rows
|
|
end
|
|
|
|
#
|
|
# Returns an array of the column vectors of the matrix. See Vector.
|
|
#
|
|
def column_vectors
|
|
columns = (0 .. column_size - 1).collect {
|
|
|i|
|
|
column(i)
|
|
}
|
|
columns
|
|
end
|
|
|
|
#
|
|
# Returns an array of arrays that describe the rows of the matrix.
|
|
#
|
|
def to_a
|
|
@rows.collect{|row| row.collect{|e| e}}
|
|
end
|
|
|
|
#--
|
|
# PRINTING -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
|
|
#++
|
|
|
|
#
|
|
# Overrides Object#to_s
|
|
#
|
|
def to_s
|
|
"Matrix[" + @rows.collect{
|
|
|row|
|
|
"[" + row.collect{|e| e.to_s}.join(", ") + "]"
|
|
}.join(", ")+"]"
|
|
end
|
|
|
|
#
|
|
# Overrides Object#inspect
|
|
#
|
|
def inspect
|
|
"Matrix"+@rows.inspect
|
|
end
|
|
|
|
# Private CLASS
|
|
|
|
class Scalar < Numeric # :nodoc:
|
|
include ExceptionForMatrix
|
|
|
|
def initialize(value)
|
|
@value = value
|
|
end
|
|
|
|
# ARITHMETIC
|
|
def +(other)
|
|
case other
|
|
when Numeric
|
|
Scalar.new(@value + other)
|
|
when Vector, Matrix
|
|
Scalar.Raise WrongArgType, other.class, "Numeric or Scalar"
|
|
when Scalar
|
|
Scalar.new(@value + other.value)
|
|
else
|
|
x, y = other.coerce(self)
|
|
x + y
|
|
end
|
|
end
|
|
|
|
def -(other)
|
|
case other
|
|
when Numeric
|
|
Scalar.new(@value - other)
|
|
when Vector, Matrix
|
|
Scalar.Raise WrongArgType, other.class, "Numeric or Scalar"
|
|
when Scalar
|
|
Scalar.new(@value - other.value)
|
|
else
|
|
x, y = other.coerce(self)
|
|
x - y
|
|
end
|
|
end
|
|
|
|
def *(other)
|
|
case other
|
|
when Numeric
|
|
Scalar.new(@value * other)
|
|
when Vector, Matrix
|
|
other.collect{|e| @value * e}
|
|
else
|
|
x, y = other.coerce(self)
|
|
x * y
|
|
end
|
|
end
|
|
|
|
def / (other)
|
|
case other
|
|
when Numeric
|
|
Scalar.new(@value / other)
|
|
when Vector
|
|
Scalar.Raise WrongArgType, other.class, "Numeric or Scalar or Matrix"
|
|
when Matrix
|
|
self * _M.inverse
|
|
else
|
|
x, y = other.coerce(self)
|
|
x.quo(y)
|
|
end
|
|
end
|
|
|
|
def ** (other)
|
|
case other
|
|
when Numeric
|
|
Scalar.new(@value ** other)
|
|
when Vector
|
|
Scalar.Raise WrongArgType, other.class, "Numeric or Scalar or Matrix"
|
|
when Matrix
|
|
other.powered_by(self)
|
|
else
|
|
x, y = other.coerce(self)
|
|
x ** y
|
|
end
|
|
end
|
|
end
|
|
end
|
|
|
|
|
|
#
|
|
# The +Vector+ class represents a mathematical vector, which is useful in its own right, and
|
|
# also constitutes a row or column of a Matrix.
|
|
#
|
|
# == Method Catalogue
|
|
#
|
|
# To create a Vector:
|
|
# * <tt> Vector.[](*array) </tt>
|
|
# * <tt> Vector.elements(array, copy = true) </tt>
|
|
#
|
|
# To access elements:
|
|
# * <tt> [](i) </tt>
|
|
#
|
|
# To enumerate the elements:
|
|
# * <tt> #each2(v) </tt>
|
|
# * <tt> #collect2(v) </tt>
|
|
#
|
|
# Vector arithmetic:
|
|
# * <tt> *(x) "is matrix or number" </tt>
|
|
# * <tt> +(v) </tt>
|
|
# * <tt> -(v) </tt>
|
|
#
|
|
# Vector functions:
|
|
# * <tt> #inner_product(v) </tt>
|
|
# * <tt> #collect </tt>
|
|
# * <tt> #map </tt>
|
|
# * <tt> #map2(v) </tt>
|
|
# * <tt> #r </tt>
|
|
# * <tt> #size </tt>
|
|
#
|
|
# Conversion to other data types:
|
|
# * <tt> #covector </tt>
|
|
# * <tt> #to_a </tt>
|
|
# * <tt> #coerce(other) </tt>
|
|
#
|
|
# String representations:
|
|
# * <tt> #to_s </tt>
|
|
# * <tt> #inspect </tt>
|
|
#
|
|
class Vector
|
|
include ExceptionForMatrix
|
|
|
|
#INSTANCE CREATION
|
|
|
|
private_class_method :new
|
|
|
|
#
|
|
# Creates a Vector from a list of elements.
|
|
# Vector[7, 4, ...]
|
|
#
|
|
def Vector.[](*array)
|
|
new(:init_elements, array, copy = false)
|
|
end
|
|
|
|
#
|
|
# Creates a vector from an Array. The optional second argument specifies
|
|
# whether the array itself or a copy is used internally.
|
|
#
|
|
def Vector.elements(array, copy = true)
|
|
new(:init_elements, array, copy)
|
|
end
|
|
|
|
#
|
|
# For internal use.
|
|
#
|
|
def initialize(method, array, copy)
|
|
self.send(method, array, copy)
|
|
end
|
|
|
|
#
|
|
# For internal use.
|
|
#
|
|
def init_elements(array, copy)
|
|
if copy
|
|
@elements = array.dup
|
|
else
|
|
@elements = array
|
|
end
|
|
end
|
|
|
|
# ACCESSING
|
|
|
|
#
|
|
# Returns element number +i+ (starting at zero) of the vector.
|
|
#
|
|
def [](i)
|
|
@elements[i]
|
|
end
|
|
|
|
#
|
|
# Returns the number of elements in the vector.
|
|
#
|
|
def size
|
|
@elements.size
|
|
end
|
|
|
|
#--
|
|
# ENUMERATIONS -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
|
|
#++
|
|
|
|
#
|
|
# Iterate over the elements of this vector and +v+ in conjunction.
|
|
#
|
|
def each2(v) # :yield: e1, e2
|
|
Vector.Raise ErrDimensionMismatch if size != v.size
|
|
0.upto(size - 1) do
|
|
|i|
|
|
yield @elements[i], v[i]
|
|
end
|
|
end
|
|
|
|
#
|
|
# Collects (as in Enumerable#collect) over the elements of this vector and +v+
|
|
# in conjunction.
|
|
#
|
|
def collect2(v) # :yield: e1, e2
|
|
Vector.Raise ErrDimensionMismatch if size != v.size
|
|
(0 .. size - 1).collect do
|
|
|i|
|
|
yield @elements[i], v[i]
|
|
end
|
|
end
|
|
|
|
#--
|
|
# COMPARING -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
|
|
#++
|
|
|
|
#
|
|
# Returns +true+ iff the two vectors have the same elements in the same order.
|
|
#
|
|
def ==(other)
|
|
return false unless Vector === other
|
|
|
|
other.compare_by(@elements)
|
|
end
|
|
alias eqn? ==
|
|
|
|
#
|
|
# For internal use.
|
|
#
|
|
def compare_by(elements)
|
|
@elements == elements
|
|
end
|
|
|
|
#
|
|
# Return a copy of the vector.
|
|
#
|
|
def clone
|
|
Vector.elements(@elements)
|
|
end
|
|
|
|
#
|
|
# Return a hash-code for the vector.
|
|
#
|
|
def hash
|
|
@elements.hash
|
|
end
|
|
|
|
#--
|
|
# ARITHMETIC -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
|
|
#++
|
|
|
|
#
|
|
# Multiplies the vector by +x+, where +x+ is a number or another vector.
|
|
#
|
|
def *(x)
|
|
case x
|
|
when Numeric
|
|
els = @elements.collect{|e| e * x}
|
|
Vector.elements(els, false)
|
|
when Matrix
|
|
Matrix.column_vector(self) * x
|
|
else
|
|
s, x = x.coerce(self)
|
|
s * x
|
|
end
|
|
end
|
|
|
|
#
|
|
# Vector addition.
|
|
#
|
|
def +(v)
|
|
case v
|
|
when Vector
|
|
Vector.Raise ErrDimensionMismatch if size != v.size
|
|
els = collect2(v) {
|
|
|v1, v2|
|
|
v1 + v2
|
|
}
|
|
Vector.elements(els, false)
|
|
when Matrix
|
|
Matrix.column_vector(self) + v
|
|
else
|
|
s, x = v.coerce(self)
|
|
s + x
|
|
end
|
|
end
|
|
|
|
#
|
|
# Vector subtraction.
|
|
#
|
|
def -(v)
|
|
case v
|
|
when Vector
|
|
Vector.Raise ErrDimensionMismatch if size != v.size
|
|
els = collect2(v) {
|
|
|v1, v2|
|
|
v1 - v2
|
|
}
|
|
Vector.elements(els, false)
|
|
when Matrix
|
|
Matrix.column_vector(self) - v
|
|
else
|
|
s, x = v.coerce(self)
|
|
s - x
|
|
end
|
|
end
|
|
|
|
#--
|
|
# VECTOR FUNCTIONS -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
|
|
#++
|
|
|
|
#
|
|
# Returns the inner product of this vector with the other.
|
|
# Vector[4,7].inner_product Vector[10,1] => 47
|
|
#
|
|
def inner_product(v)
|
|
Vector.Raise ErrDimensionMismatch if size != v.size
|
|
|
|
p = 0
|
|
each2(v) {
|
|
|v1, v2|
|
|
p += v1 * v2
|
|
}
|
|
p
|
|
end
|
|
|
|
#
|
|
# Like Array#collect.
|
|
#
|
|
def collect # :yield: e
|
|
els = @elements.collect {
|
|
|v|
|
|
yield v
|
|
}
|
|
Vector.elements(els, false)
|
|
end
|
|
alias map collect
|
|
|
|
#
|
|
# Like Vector#collect2, but returns a Vector instead of an Array.
|
|
#
|
|
def map2(v) # :yield: e1, e2
|
|
els = collect2(v) {
|
|
|v1, v2|
|
|
yield v1, v2
|
|
}
|
|
Vector.elements(els, false)
|
|
end
|
|
|
|
#
|
|
# Returns the modulus (Pythagorean distance) of the vector.
|
|
# Vector[5,8,2].r => 9.643650761
|
|
#
|
|
def r
|
|
v = 0
|
|
for e in @elements
|
|
v += e*e
|
|
end
|
|
return Math.sqrt(v)
|
|
end
|
|
|
|
#--
|
|
# CONVERTING
|
|
#++
|
|
|
|
#
|
|
# Creates a single-row matrix from this vector.
|
|
#
|
|
def covector
|
|
Matrix.row_vector(self)
|
|
end
|
|
|
|
#
|
|
# Returns the elements of the vector in an array.
|
|
#
|
|
def to_a
|
|
@elements.dup
|
|
end
|
|
|
|
#
|
|
# FIXME: describe Vector#coerce.
|
|
#
|
|
def coerce(other)
|
|
case other
|
|
when Numeric
|
|
return Scalar.new(other), self
|
|
else
|
|
raise TypeError, "#{self.class} can't be coerced into #{other.class}"
|
|
end
|
|
end
|
|
|
|
#--
|
|
# PRINTING -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
|
|
#++
|
|
|
|
#
|
|
# Overrides Object#to_s
|
|
#
|
|
def to_s
|
|
"Vector[" + @elements.join(", ") + "]"
|
|
end
|
|
|
|
#
|
|
# Overrides Object#inspect
|
|
#
|
|
def inspect
|
|
str = "Vector"+@elements.inspect
|
|
end
|
|
end
|
|
|
|
|
|
# Documentation comments:
|
|
# - Matrix#coerce and Vector#coerce need to be documented
|