Added a lot to Matrix

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Chris Watson 2019-06-11 23:33:15 -07:00
parent 131ab63faf
commit 1b69ec120e
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2 changed files with 426 additions and 28 deletions

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@ -6,18 +6,21 @@ module Apatite
include Indexable(Vector)
include Comparable(Matrix)
@col_count : Int32
getter column_count : Int32
getter row_count : Int32
@buffer : Pointer(Vector)
def initialize(rows : Array(Indexable(Number)), col_count : Int32 = rows[0].size)
@buffer = rows.map { |r| Vector.create(r) }.to_unsafe
@col_count = col_count
def initialize(rows, column_count : Int32 = rows[0].size)
@buffer = rows.map { |r| Vector.create(r) }.to_a.to_unsafe
@row_count = rows.size
@column_count = column_count
end
# Creates a matrix where each argument is a row.
def self.[](*rows)
rows(rows, false)
rows(rows)
end
# Creates a matrix of size `row_count x column_count`. It fills the values by calling
@ -39,28 +42,29 @@ module Apatite
# Creates a matrix using `columns` as an array of column vectors.
def self.columns(columns)
rows(columns, false).transpose
rows(columns).transpose
end
# Create a matrix by combining matrices entrywise, using the given block.
def self.combine(matrices, &block)
return Matrix.empty if matrices.empty?
x = matrices.first
matrices.each do |m|
rase "Dimension mismatch" unless x.row_count == m.row_count && x.column_count == m.column_count
end
# # Create a matrix by combining matrices entrywise, using the given block.
# def self.combine(matrices : Array(Matrix), &block : Matrix -> Matrix -> Matrix)
# return Matrix.empty if matrices.empty?
# x = matrices.first
# matrices.each do |m|
# raise "Dimension mismatch" unless x.row_count == m.row_count && x.column_count == m.column_count
# end
rows = Array.new(x.row_count) do |i|
Vector.new(x.column_count) do |j|
yield matrices.map{|m| m[i,j]}
end
end
new rows, x.column_count
end
# rows = Array.new(x.row_count) do |i|
# Vector.new(x.column_count) do |j|
# yield matrices.map { |m| m[i, j] }
# end
# end
def self.combine(*matrices, &block)
Matrix.combine(matrices, &block)
end
# Matrix.new(rows, x.column_count)
# end
# def self.combine(*matrices, &block : Matrix -> Matrix)
# Matrix.combine(matrices, &block)
# end
# Creates a matrix where the diagonal elements are composed of `values`.
def self.diagonal(values)
@ -100,7 +104,7 @@ module Apatite
# Creates a single-row matrix where the values of that row are as given in `row`.
def self.row_vector(row)
Matrix.new([row])
Matrix.new([row], 0)
end
# Creates a matrix where rows is an array of arrays, each of which is a row of the matrix.
@ -126,5 +130,399 @@ module Apatite
rows = Array.new(row_count) { Vector.new(column_count) }
Matrix.new(rows, column_count)
end
def *(other : Matrix)
raise "Dimension mismatch" if column_count != other.column_count
rows = Array.new(row_count) do |i|
Vector.new(other.column_count) do |j|
(0...column_count).reduce(0.0) do |vij, k|
vij + self[i, k] * other[k, j]
end
end
end
return Matrix.new(rows, other.column_count)
end
def *(int : Int)
rows = self.rows.map do |row|
row.map { |e| e * int }
end
Matrix.new(rows, column_count)
end
def *(ind : Indexable)
m = column_vector
r = self * m
r.column(0)
end
def **(int)
raise "Number can not the less than 1" unless int >= 1
mat = self
(int - 1).times do
mat = mat * self
end
mat
end
def +(other : Matrix)
raise "Dimension mismatch" if column_count != other.column_count
rows = Array.new(row_count) do |i|
Vector.new(other.column_count) do |j|
self[i, j] + other[i, j]
end
end
return Matrix.new(rows, other.column_count)
end
def +(vec : Indexable)
vec = vec.is_a?(Vector) ? vec : Vector.create(vec)
self + column_vector(vec)
end
def -(other : Matrix)
raise "Dimension mismatch" if column_count != other.column_count
rows = Array.new(row_count) do |i|
Vector.new(other.column_count) do |j|
self[i, j] - other[i, j]
end
end
return Matrix.new(rows, other.column_count)
end
def -(vec : Indexable)
vec = vec.is_a?(Vector) ? vec : Vector.create(vec)
self + column_vector(vec)
end
def /(other : Matrix)
self * other.inverse
end
def /(vec : Indexable)
rows = self.rows.map { |row|
row.map { |e| e / other }
}
return new_matrix rows, column_count
end
def ==(other : Matrix)
return false unless Matrix === other &&
column_count == other.column_count # necessary for empty matrices
rows == other.rows
end
# Returns element `(row, col)` of the matrix. Throws error on index error.
def [](row : Int, col : Int)
self[row][col]
end
# Returns element `(row, col)` of the matrix, or nil if the index is not found.
def []?(row : Int, col : Int)
v = fetch(row) { nil }
v[col]? unless v.nil?
end
# Returns the adjugate of the matrix.
def adjugate
raise "Dimention mismatch: `Matrix#adjugate` requires a square matrix." unless square?
Matrix.build(row_count, column_count) do |row, column|
cofactor(column, row)
end
end
# Returns the (row, column) cofactor which is obtained by multiplying the first minor by (-1)**(row + column)
def cofactor(row, column)
raise "cofactor of empty matrix is not defined" if empty?
raise "Dimention mismatch: `Matrix#cofactor` requires a square matrix." unless square?
det_of_minor = first_minor(row, column).determinant
det_of_minor * (-1.0) ** (row + column)
end
# Returns column vector number `j` of the matrix as a `Vector` (starting at 0 like an array).
def column?(j)
return nil if j >= column_count || j < -column_count
col = Array(Float64).new(row_count) { |i|
rows[i][j]
}
Vector.create(col)
end
# Returns column vector number `j` of the matrix as a `Vector` (starting at 0 like an array).
def column(j)
raise "Index out of range" if j >= column_count || j < -column_count
col = Array(Float64).new(row_count) { |i|
rows[i][j]
}
Vector.create(col)
end
# Iterates over the specified column in the matrix, returning the Vector's items.
def column(j, &block)
return self if j >= column_count || j < -column_count
row_count.times do |i|
yield rows[i][j]
end
self
end
# Returns an array of the column vectors of the matrix. See `Vector`.
def column_vectors
Array(Vector).new(column_count) { |i|
column(i)
}
end
# def combine(*matrices, &block)
# Matrix.combine(self, matrices, &block)
# end
# # Hadamard product
# def hadamard_product(m)
# combine(m){|a, b| a * b}
# end
# # Returns a new matrix resulting by stacking horizontally the receiver with the given matrices
# def hstack(*matrices)
# Matrix.hstack(self, *matrices)
# end
# Returns the inverse of the matrix.
def inverse
raise "Dimention mismatch: `Matrix#inverse` requires a square matrix." unless square? unless square?
Matrix.identity(row_count).inverse_from(self)
end
# :nodoc:
def inverse_from(src)
last = row_count - 1.0
a = src.to_a
0.upto(last) do |k|
i = k
akk = a[k][k].abs
(k + 1).upto(last) do |j|
v = a[j][k].abs
if v > akk
i = j
akk = v
end
end
raise "Not regular" if akk == 0
if i != k
a[i], a[k] = a[k], a[i]
rows[i], rows[k] = rows[k], rows[i]
end
akk = a[k][k]
0.upto(last) do |ii|
next if ii == k
q = a[ii][k] / akk
a[ii][k] = 0.0
(k + 1).upto(last) do |j|
a[ii][j] -= a[k][j] * q
end
0.upto(last) do |j|
rows[ii][j] -= rows[k][j] * q
end
end
(k + 1).upto(last) do |j|
a[k][j] = a[k][j] / akk
end
0.upto(last) do |j|
rows[k][j] = rows[k][j] / akk
end
end
self
end
def determinant
raise "Dimention mismatch: `Matrix#determinant` requires a square matrix." unless square?
m = rows
case row_count
# Up to 4x4, give result using Laplacian expansion by minors.
# This will typically be faster, as well as giving good results
# in case of Floats
when 0
+1
when 1
+m[0][0]
when 2
+m[0][0] * m[1][1] - m[0][1] * m[1][0]
when 3
m0, m1, m2 = m
+m0[0] * m1[1] * m2[2] - m0[0] * m1[2] * m2[1] \
- m0[1] * m1[0] * m2[2] + m0[1] * m1[2] * m2[0] \
+ m0[2] * m1[0] * m2[1] - m0[2] * m1[1] * m2[0]
when 4
m0, m1, m2, m3 = m
+m0[0] * m1[1] * m2[2] * m3[3] - m0[0] * m1[1] * m2[3] * m3[2] \
- m0[0] * m1[2] * m2[1] * m3[3] + m0[0] * m1[2] * m2[3] * m3[1] \
+ m0[0] * m1[3] * m2[1] * m3[2] - m0[0] * m1[3] * m2[2] * m3[1] \
- m0[1] * m1[0] * m2[2] * m3[3] + m0[1] * m1[0] * m2[3] * m3[2] \
+ m0[1] * m1[2] * m2[0] * m3[3] - m0[1] * m1[2] * m2[3] * m3[0] \
- m0[1] * m1[3] * m2[0] * m3[2] + m0[1] * m1[3] * m2[2] * m3[0] \
+ m0[2] * m1[0] * m2[1] * m3[3] - m0[2] * m1[0] * m2[3] * m3[1] \
- m0[2] * m1[1] * m2[0] * m3[3] + m0[2] * m1[1] * m2[3] * m3[0] \
+ m0[2] * m1[3] * m2[0] * m3[1] - m0[2] * m1[3] * m2[1] * m3[0] \
- m0[3] * m1[0] * m2[1] * m3[2] + m0[3] * m1[0] * m2[2] * m3[1] \
+ m0[3] * m1[1] * m2[0] * m3[2] - m0[3] * m1[1] * m2[2] * m3[0] \
- m0[3] * m1[2] * m2[0] * m3[1] + m0[3] * m1[2] * m2[1] * m3[0]
else
# For bigger matrices, use an efficient and general algorithm.
# Currently, we use the Gauss-Bareiss algorithm
determinant_bareiss
end
end
# Returns the determinant of the matrix, using
# Bareiss' multistep integer-preserving gaussian elimination.
# It has the same computational cost order O(n^3) as standard Gaussian elimination.
# Intermediate results are fraction free and of lower complexity.
# A matrix of Integers will have thus intermediate results that are also Integers,
# with smaller bignums (if any), while a matrix of Float will usually have
# intermediate results with better precision.
#
private def determinant_bareiss
size = row_count
last = size - 1
a = to_a
no_pivot = Proc(Int32).new { return 0 }
sign = +1
pivot = 1
size.times do |k|
previous_pivot = pivot
if (pivot = a[k][k]) == 0
switch = (k + 1...size).find(0) { |row|
a[row][k] != 0
}
a[switch], a[k] = a[k], a[switch]
pivot = a[k][k]
sign = -sign
end
(k + 1).upto(last) do |i|
ai = a[i]
(k + 1).upto(last) do |j|
ai[j] = (pivot * ai[j] - ai[k] * a[k][j]) / previous_pivot
end
end
end
sign * pivot
end
def first_minor(row, column)
raise "first_minor of empty matrix is not defined" if empty?
unless 0 <= row && row < row_count
raise ArgumentError.new("invalid row (#{row.inspect} for 0..#{row_count - 1})")
end
unless 0 <= column && column < column_count
raise ArgumentError.new("invalid column (#{column.inspect} for 0..#{column_count - 1})")
end
arrays = to_a.map(&.to_a)
arrays.delete_at(row)
arrays.each do |array|
array.delete_at(column)
end
Matrix.new(arrays, column_count - 1)
end
# Returns the Laplace expansion along given row or column.
def laplace_expansion(*, row = nil, column = nil)
num = row || column
if !num || (row && column)
raise ArgumentError.new("exactly one the row or column arguments must be specified")
end
raise "Dimention mismatch: `Matrix#determinant` requires a square matrix." unless square?
raise "laplace_expansion of empty matrix is not defined" if empty?
unless 0 <= num && num < row_count
raise ArgumentError.new("invalid num (#{num.inspect} for 0..#{row_count - 1})")
end
if row
row(num).map_with_index { |e, k|
e * cofactor(num, k)
}.reduce(&.+)
else
column(num).map_with_index { |e, k|
e * cofactor(k, num)
}.reduce(&.+)
end
end
def row(i, &block)
@rows.fetch(i){return self}.each(&block)
self
end
def row(i)
Vector.create(rows.fetch(i) { [] of Float64 })
end
def rows
rows = [] of Vector
row_count.times do |i|
rows << self[i - 1]
end
rows
end
def square?
row_count == column_count
end
def transpose
return Matrix.empty(column_count, 0) if row_count.zero?
transposed = rows.map { |v| v.to_a }.transpose
Matrix.new(transposed, row_count)
end
def to_s(io)
if empty?
"Matrix.empty(#{row_count}, #{column_count})"
else
io << "Matrix["
io << map { |row|
"{" + row.to_a.map { |e| e.to_s }.join(", ") + "}"
}.join(", ")
io << "]"
end
end
def pretty_print(pp) : Nil
pp.list("[", self, "]") do |vec|
pp.group do
vec.to_a.pretty_print(pp)
end
end
end
@[AlwaysInline]
def unsafe_fetch(index : Int)
@buffer[index]
end
# To be in compliance with `Indexable`
private def size
@row_count
end
end
end

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@ -614,7 +614,7 @@ module Apatite
# Transpose this vector into a 1xn `Matrix`
def transpose
Matrix.column_vector(self)
Matrix.col_vector(self)
end
# Returns a copy of the vector with elements set to `value` if
@ -739,7 +739,7 @@ module Apatite
end
def to_s(io)
io << "Vector{"
io << "{"
join ", ", io, &.inspect(io)
io << "}"
end
@ -810,9 +810,9 @@ module Apatite
return map { |v| yield(v, value) }
end
values = value.is_a?(Vector) ? value.elements : value
values = value.is_a?(Vector) ? value : Vector.create(value)
unless @elements.size == values.size
unless size == values.size
raise "Cannot perform operations on vectors with different dimensions."
end