jacobub / matrix

A Matrix class for the Crystal programming language.

matrix

This is a Matrix class for Crystal. There are a few ways to create a Matrix:

# Creates a Matrix of Int32 with 3 rows and 2 columns. A Tuple of rows can also 
# be used instead of an array. Each row must have the same number of elements.
Matrix.rows([[1, 2], [3, 4], [5, 6]]) 
# 1, 2
# 3, 4
# 5, 6

# Creates a Matrix with 2 rows and 3 columns. Like with Matrix.rows, the columns 
# must have the same number of elements.
Matrix.columns([[1, 2], [3, 4], [5, 6]])
# 1, 3, 5
# 2, 4, 6

# A Matrix can also be created by giving its number of columns and rows, just 
# like an Array can be created by giving it a starting size. This constructor 
# will yield the linear index, the current row and the current column.
Matrix.new(2, 2) { |idx, row, col| idx  }
# 0, 1
# 2, 3
Matrix.new(2, 2) { |idx, row, col| row  }
# 0, 0
# 1, 1
Matrix.new(2, 2) { |idx, row, col| col  }
 # 0, 1
 # 0, 1

Most methods are documented in the matrix.cr file itself.

matrix's Issues

to_a should return a multidimensional array

I feel like it would make sense since this is a matrix, that to_a would return a multidimensional array. Or maybe there could be a to_multi method or something?

Typo in #swap_columns

you're missing an 'r': https://github.com/Exilor/matrix/blob/master/src/matrix.cr#L784

Spec Fails in Crystal version 0.34.0

Trying to use the Matrix shard, running spec causes below fail:
root@ROB-MSI:/mnt/d/Workspace/matrix# crystal spec --error-trace
error in line 1
Error: while requiring "./spec/matrix_spec.cr"
In spec/matrix_spec.cr:245:21
245 | m.determinant.should be_close(1.25922e+45, 1e40)
^-----
Error: instantiating '(Float64 | Int32 | Nil)#should(Spec::CloseExpectation(Float64, Float64))'
In /usr/share/crystal/src/spec/expectations.cr:446:26
446 | unless expectation.match self
^----
Error: instantiating 'Spec::CloseExpectation(Float64, Float64)#match(Nil)'

In /usr/share/crystal/src/spec/expectations.cr:127:21
127 | (actual_value - @expected_value).abs <= @delta
^
Error: undefined method '-' for Nil

Nil trace:
/usr/share/crystal/src/spec/expectations.cr:127
(actual_value - @expected_value).abs <= @delta

/usr/share/crystal/src/spec/expectations.cr:126
def match(actual_value)

Also seeing a similar error in the transpose function as well.

Can't run specs, compilation fails

Hi,

I thought I'd try upgrading some code to Crystal 0.16.0, but the compiler failed with a problem in the matrix code (on which my code relies). I tried running the specs for the matrix shard and the compiler doesn't like what it sees:

$ crystal spec
Error in ./spec/matrix_spec.cr:7: instantiating 'Matrix(T):Class#rows(Array(Array(Int32)))'

      m = Matrix.rows([[1, 2], [3, 4], [5, 6]])
                 ^~~~

in ./src/matrix.cr:60: instantiating 'Matrix(T):Class#new(Int32, Int32)'

    Matrix.new(rows.size.to_i32, rows.first.size.to_i32) do |i, r, c|
           ^~~

in ./src/matrix.cr:38: instantiating 'Matrix(Int32):Class#new(Int32, Int32)'

    matrix = Matrix(T).new(rows, columns)
                       ^~~

instantiating 'Matrix(Int32)#initialize(Int32, Int32)'

in ./src/matrix.cr:28: instantiating 'size()'

    @buffer = Pointer(T).malloc(size)
                                ^~~~

in ./src/matrix.cr:454: undefined method '*' for Int+ (compile-time type is (Int+ | Int32))

    @rows * @columns
          ^


$ crystal --version
Crystal 0.16.0 (Sun May  8 12:21:15 UTC 2016)

I almost think this is a problem with Crystal itself, given that I'm not really sure what an Int+ is, but thought I'd check here first. If you think I should file a bug in the main Crystal repo let me know, I'm happy to do that. Thanks!