rsc3/doc-schelp/HelpSource/Classes/Array2D.schelp

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CLASS::Array2D
summary::two-dimensional array
related::Classes/Array
categories::Collections>Ordered
DESCRIPTION::
Represents a two-dimensional array of data. The number of rows and columns is fixed.
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.::
CLASSMETHODS::
method::new
Create an array of the specified size.
code::
a = Array2D.new(3,4);
a[2,2] = 1;
a.postln
::
method::fromArray
Build an Array2D from the supplied array.
code::
a = Array2D.fromArray(3,4, [9,8,7,6,5,4,3,2,1,2,3,4]);
a[2,2] = 1;
a.postln
::
INSTANCEMETHODS::
private::printOn, storeOn
method::at
Get a value from the array.
code::
a.at(2,3);
a[2,3];
::
method::put
Put a value into the array.
code::
a.put(2,3, 72);
a[2,3] = 72;
::
method::colsDo
Iterate over the columns. Each column will be passed to strong::func:: in turn.
code::
a.colsDo(_.postln);
::
method::rowsDo
Iterate over the rows. Each row will be passed to strong::func:: in turn.
code::
a.rowsDo(_.postln);
::
method::colAt
Retrieve a single column.
code::
a.colAt(2);
::
method::rowAt
Retrieve a single row.
code::
a.rowAt(2);
::
method::asArray
Return a flat array containing the elements.
code::
a.postln;
a.asArray.postln;
::
returns:: link::Classes/Array::
EXAMPLES::
code::
// "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 }) }
::