Array2D Two-dimensional array

Inherits from: Collection

Represents a two-dimensional array of data. The number of rows and columns is fixed.

See also: Array

Note: It is possible to implement a similar behaviour using an "array-of-arrays" - see the examples towards the bottom of this page for comparison.

Creation / Class Methods

*new(rows, cols)

Create an array of the specified size.

a = Array2D.new(3,4);

a[2,2] = 1;

a.postln

*fromArray(rows, cols, array)

Build an Array2D from the supplied array.

a = Array2D.fromArray(3,4, [9,8,7,6,5,4,3,2,1,2,3,4]);

a[2,2] = 1;

a.postln

Instance Methods

at(row, col)

Get a value from the array.

a.at(2,3);

a[2,3];

put(row, col, val)

Put a value into the array.

a.put(2,3, 72);

a[2,3];

colsDo(function)

rowsDo(function)

Iterate over the columns, or the rows. Each row or column will be passed to function in turn.

a.colsDo(_.postln);

a.rowsDo(_.postln);

colAt(index)

rowAt(index)

Retrieve a single row, or column.

a.colAt(2)

a.rowAt(2)

asArray

Return a flat array containing the elements.

a.postln

a.asArray.postln;

Examples

// "a" is an array-of-arrays

a = {{100.0.rand}.dup(100)}.dup(100);

// "b" is an equivalent Array2D, made using the "fromArray" class method

b = Array2D.fromArray(100,100, a.flat);

// Accessing

a[15][22]

b[15, 22]

// Speed comparison 1: random access

bench{100.do(a[100.rand][100.rand])}

bench{100.do(b[100.rand, 100.rand])}

// Speed comparison 2: iteration

bench{100.do(a.do{|row| row.do{|item| item * 2}})}

bench{100.do(b.do{|item| item * 2})}