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Matrix

A matrix is a 2-dimensional array of numbers used for linear algebra operations. Matrices are created by calling the to_m() method on nested arrays.

Matrix supports mathematical operations:

  • Matrix multiplication: m1 * m2
  • Element-wise addition: m1 + m2
  • Element-wise subtraction: m1 - m2

Matrix indexing:

  • m[i] returns row i as an array
  • m[i][j] returns the element at row i, column j
  • Negative indices are supported: m[-1] returns the last row
m1 = [[1, 2], [3, 4]].to_m()
m2 = [[5, 6], [7, 8]].to_m()

result = m1 * m2
sum = m1 + m2
diff = m2 - m1

puts(result)

// should output
2x2 matrix
┌            ┐
│ 19.0  22.0 │
│ 43.0  50.0 │
└            ┘

Literal Specific Methods​

col(INTEGER)​

Returns ARRAY|ERROR

Returns the specified column as an array (0-indexed).

m = [[1, 2, 3], [4, 5, 6]].to_m()
m.col(1)
Output
[2.0, 5.0]

cols()​

Returns INTEGER

Returns the number of columns in the matrix.

m = [[1, 2, 3], [4, 5, 6]].to_m()
m.cols()
Output
3

get(INTEGER, INTEGER)​

Returns FLOAT|ERROR

Returns the element at the specified row and column (0-indexed).

m = [[1, 2, 3], [4, 5, 6]].to_m()
m.get(0, 2)
Output
3.0

row(INTEGER)​

Returns ARRAY|ERROR

Returns the specified row as an array (0-indexed).

m = [[1, 2, 3], [4, 5, 6]].to_m()
m.row(0)
Output
[1.0, 2.0, 3.0]

rows()​

Returns INTEGER

Returns the number of rows in the matrix.

m = [[1, 2, 3], [4, 5, 6]].to_m()
m.rows()
Output
2

set(INTEGER, INTEGER, FLOAT|INTEGER)​

Returns NIL|ERROR

Sets the element at the specified row and column (0-indexed).

m = [[1, 2, 3], [4, 5, 6]].to_m()
m.set(0, 2, 99)
m
Output
2x3 matrix
┌               ┐
│ 1.0  2.0  3.0 │
│ 4.0  5.0  6.0 │
└               ┘
nil
2x3 matrix
┌                ┐
│ 1.0   2.0  99.0 │
│ 4.0   5.0   6.0 │
└                ┘

shape()​

Returns ARRAY

Returns an array containing the dimensions [rows, cols] of the matrix.

m = [[1, 2, 3], [4, 5, 6]].to_m()
m.shape()
Output
[2, 3]

size()​

Returns INTEGER

Returns the total number of elements in the matrix (rows * cols).

m = [[1, 2, 3], [4, 5, 6]].to_m()
m.size()
Output
6

t()​

Returns MATRIX

Alias for transpose(). Returns the transposed matrix.

m = [[1, 2], [3, 4]].to_m()
m.t()
Output
2x2 matrix
┌          ┐
│ 1.0  3.0 │
│ 2.0  4.0 │
└          ┘

to_a()​

Returns ARRAY

Converts the matrix back to a nested array representation.

m = [[1, 2], [3, 4]].to_m()
m.to_a()
Output
[[1.0, 2.0], [3.0, 4.0]]

transpose()​

Returns MATRIX

Returns the transposed matrix (rows and columns swapped).

m = [[1, 2, 3], [4, 5, 6]].to_m()
m.transpose()
Output
3x2 matrix
┌          ┐
│ 1.0  4.0 │
│ 2.0  5.0 │
│ 3.0  6.0 │
└          ┘

Generic Literal Methods​

methods()​

Returns ARRAY

Returns an array of all supported methods names.

"test".methods()
Output
["upcase", "find", "format", "reverse", "split", "replace", "strip!", "count", "reverse!", "lines", "downcase!", "upcase!", "size", "strip", "downcase"]

to_f()​

Returns FLOAT

If possible converts an object to its float representation. If not 0.0 is returned.

1.to_f()
"1.4".to_f()
nil.to_f()
Output
1.0
1.4
0.0

to_i(INTEGER)​

Returns INTEGER

If possible converts an object to its integer representation. If not 0 is returned.

true.to_i()
false.to_i()
1234.to_i()
"4".to_i()
"10011010010"to_i(2)
"2322".to_i(8)
"0x2322".to_i()
Output
1
0
1234
4
1234
1234
1234

to_json()​

Returns STRING|ERROR

Returns the object as json notation.

a = {"test": 1234}
a.to_json()
Output
{"test": 1234}
"{\"test\":1234}"

to_s(INTEGER)​

Returns STRING

If possible converts an object to its string representation. If not empty string is returned.

true.to_s()
1234.to_s()
1234.to_s(2)
1234.to_s(8)
1234.to_s(10)
"test".to_s()
1.4.to_s()
Output
"true"
"1234"
"10011010010"
"2322"
"1234"
"test"
"1.4"

type()​

Returns STRING

Returns the type of the object.

"test".type()
Output
"STRING"

wat()​

Returns STRING

Returns the supported methods with usage information.

true.wat()
Output
"BOOLEAN supports the following methods:
to_s()"