Feature #2771: Matrix: constructor to build with block

• Status: Closed
• Assignee: marcandre (Marc-Andre Lafortune)
• Target version: 1.9.2

[marcandre (Marc-Andre Lafortune)]

=begin
I believe the following simple constructor could be a helpful addition to matrix.rb

class Matrix

Creates a matrix of +row_size+ x +column_size+.

It fills the values by calling the given block,

passing the current row and column.

m = Matrix.build(2, 4) {|row, col| col - row }

=> Matrix[[0, 1, 2, 3], [-1, 0, 1, 2]]

m = Matrix.build(3) { rand }

=> a 3x3 matrix with random elements

def self.build(row_size, column_size = row_size)
raise ArgumentError if row_size < 0 || column_size < 0
return to_enum :build, row_size, column_size unless block_given?
rows = row_size.times.map do |i|
column_size.times.map do |j|
yield i, j
end
end
new rows, column_size
end
end
=end

[keiju (Keiju Ishitsuka)]

=begin
Hi, Marc-André

Please commit it.
=end

[marcandre (Marc-Andre Lafortune)]

• Status changed from Open to Assigned
• Assignee changed from keiju (Keiju Ishitsuka) to marcandre (Marc-Andre Lafortune)

=begin

=end

[marcandre (Marc-Andre Lafortune)]

• Status changed from Assigned to Closed
• % Done changed from 0 to 100

=begin
This issue was solved with changeset r27315.
Marc-Andre, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

=end