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* lib/matrix.rb: add Matrix#determinant_e, Matrix#rank_e.

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[ruby-dev:27820] and related thread.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@9666 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
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keiju 2005-12-09 16:10:45 +00:00
parent 00f96715f3
commit 937731e7f8
2 changed files with 143 additions and 12 deletions
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5
ChangeLog
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@ -1,3 +1,8 @@
Sat Dec 10 01:06:06 2005 Keiju Ishitsuka <keiju@ruby-lang.org>
* lib/matrix.rb: add Matrix#determinant_e, Matrix#rank_e.
[ruby-dev:27820] and related thread.
Sat Dec 10 00:31:42 2005 Nobuyoshi Nakada <nobu@ruby-lang.org>
* eval.c (calling_scope_t): gave names to magic numbers for rb_call().

150
lib/matrix.rb
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@ -1,9 +1,9 @@
#!/usr/local/bin/ruby
#--
# matrix.rb -
# $Release Version: 1.0$
# $Revision: 1.11 $
# $Date: 1999/10/06 11:01:53 $
# $Release Version: 1.0$
# $Revision: 1.13 $
# $Date: 2001/12/09 14:22:23 $
# Original Version from Smalltalk-80 version
# on July 23, 1985 at 8:37:17 am
# by Keiju ISHITSUKA
@ -105,7 +105,7 @@ end
# * <tt> #inspect </tt>
#
class Matrix
@RCS_ID='-$Id: matrix.rb,v 1.11 1999/10/06 11:01:53 keiju Exp keiju $-'
@RCS_ID='-$Id: matrix.rb,v 1.13 2001/12/09 14:22:23 keiju Exp keiju $-'
# extend Exception2MessageMapper
include ExceptionForMatrix
@ -265,6 +265,15 @@ class Matrix
def [](i, j)
@rows[i][j]
end
alias element []
alias component []
def []=(i, j, v)
@rows[i][j] = v
end
alias set_element []=
alias set_component []=
private :[]=, :set_element, :set_component
#
# Returns the number of rows.
@ -320,7 +329,7 @@ class Matrix
#
# Returns a matrix that is the result of iteration of the given block over all
# elements of the matrix.
# Matrix[ [1,2], [3,4] ].collect { |i| i**2 }
# Matrix[ [1,2], [3,4] ].collect { |e| e**2 }
# => 1 4
# 9 16
#
@ -668,9 +677,13 @@ class Matrix
#
# Returns the determinant of the matrix. If the matrix is not square, the
# result is 0.
# result is 0. This method's algorism is Gaussian elimination method
# and using Numeric#quo(). Beware that using Float values, with their
# usual lack of precision, can affect the value returned by this method. Use
# Rational values or Matrix#det_e instead if this is important to you.
#
# Matrix[[7,6], [3,9]].determinant
# => 63
# => 63.0
#
def determinant
return 0 unless square?
@ -703,11 +716,56 @@ class Matrix
det
end
alias det determinant
#
# Returns the determinant of the matrix. If the matrix is not square, the
# result is 0. This method's algorism is Gaussian elimination method.
# This method uses Euclidean algorism. If all elements are integer,
# really exact value. But, if an element is a float, can't return
# exact value.
#
# Matrix[[7,6], [3,9]].determinant
# => 63
#
def determinant_e
return 0 unless square?
size = row_size - 1
a = to_a
det = 1
k = 0
begin
if a[k][k].zero?
i = k
begin
return 0 if (i += 1) > size
end while a[i][k].zero?
a[i], a[k] = a[k], a[i]
det *= -1
end
(k + 1).upto(size) do |i|
q = a[i][k] / a[k][k]
k.upto(size) do |j|
a[i][j] -= a[k][j] * q
end
unless a[i][k].zero?
a[i], a[k] = a[k], a[i]
det *= -1
redo
end
end
det *= a[k][k]
end while (k += 1) <= size
det
end
alias det_e determinant_e
#
# Returns the rank of the matrix. Beware that using Float values,
# probably return faild value. Use Rational values or Matrix#rank_e
# for getting exact result.
#
# 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
#
@ -769,6 +827,41 @@ class Matrix
return rank
end
#
# Returns the rank of the matrix. This method uses Euclidean
# algorism. If all elements are integer, really exact value. But, if
# an element is a float, can't return exact value.
#
# Matrix[[7,6], [3,9]].rank
# => 2
#
def rank_e
a = to_a
a_column_size = column_size
a_row_size = row_size
pi = 0
(0 ... a_column_size).each do |j|
if i = (pi ... a_row_size).find{|i0| !a[i0][j].zero?}
if i != pi
a[pi], a[i] = a[i], a[pi]
end
(pi + 1 ... a_row_size).each do |k|
q = a[k][j] / a[pi][j]
(pi ... a_column_size).each do |j0|
a[k][j0] -= q * a[pi][j0]
end
if k > pi && !a[k][j].zero?
a[k], a[pi] = a[pi], a[k]
redo
end
end
pi += 1
end
end
pi
end
#
# Returns the trace (sum of diagonal elements) of the matrix.
# Matrix[[7,6], [3,9]].trace
@ -844,6 +937,18 @@ class Matrix
@rows.collect{|row| row.collect{|e| e}}
end
def elements_to_f
collect{|e| e.to_f}
end
def elements_to_i
collect{|e| e.to_i}
end
def elements_to_r
collect{|e| e.to_r}
end
#--
# PRINTING -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
#++
@ -922,7 +1027,7 @@ class Matrix
when Vector
Scalar.Raise WrongArgType, other.class, "Numeric or Scalar or Matrix"
when Matrix
self * _M.inverse
self * other.inverse
else
x, y = other.coerce(self)
x.quo(y)
@ -1034,6 +1139,15 @@ class Vector
def [](i)
@elements[i]
end
alias element []
alias component []
def []=(i, v)
@elements[i]= v
end
alias set_element []=
alias set_component []=
private :[]=, :set_element, :set_component
#
# Returns the number of elements in the vector.
@ -1236,6 +1350,18 @@ class Vector
@elements.dup
end
def elements_to_f
collect{|e| e.to_f}
end
def elements_to_i
collect{|e| e.to_i}
end
def elements_to_r
collect{|e| e.to_r}
end
#
# FIXME: describe Vector#coerce.
#