141 lines
2.1 KiB
Text
141 lines
2.1 KiB
Text
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#lang scribble/manual
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@(require (for-label racket))
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@title{Array2D}
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two-dimensional array@section{related}
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Classes/Array
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@section{categories}
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Collections>Ordered
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@section{description}
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Represents a two-dimensional array of data. The number of rows and columns is fixed.
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@section{note}
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It is possible to implement a similar behaviour using an "array-of-arrays" - see the examples towards the bottom of this page for comparison.::
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@section{CLASSMETHODS}
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@section{method}
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new
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Create an array of the specified size.
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@racketblock[
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a = Array2D.new(3,4);
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a[2,2] = 1;
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a.postln
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::
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]
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@section{method}
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fromArray
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Build an Array2D from the supplied array.
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@racketblock[
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a = Array2D.fromArray(3,4, [9,8,7,6,5,4,3,2,1,2,3,4]);
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a[2,2] = 1;
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a.postln
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::
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]
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@section{INSTANCEMETHODS}
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@section{private}
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printOn, storeOn
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@section{method}
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at
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Get a value from the array.
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@racketblock[
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a.at(2,3);
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a[2,3];
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::
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]
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@section{method}
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put
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Put a value into the array.
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@racketblock[
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a.put(2,3, 72);
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a[2,3] = 72;
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::
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]
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@section{method}
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colsDo
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Iterate over the columns. Each column will be passed to strong::func:: in turn.
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@racketblock[
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a.colsDo(_.postln);
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::
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]
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@section{method}
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rowsDo
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Iterate over the rows. Each row will be passed to strong::func:: in turn.
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@racketblock[
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a.rowsDo(_.postln);
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::
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]
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@section{method}
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colAt
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Retrieve a single column.
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@racketblock[
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a.colAt(2);
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::
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]
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@section{method}
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rowAt
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Retrieve a single row.
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@racketblock[
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a.rowAt(2);
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::
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]
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@section{method}
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asArray
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Return a flat array containing the elements.
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@racketblock[
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a.postln;
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a.asArray.postln;
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::
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]
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@section{returns}
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link::Classes/Array::
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@section{EXAMPLES}
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@racketblock[
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// "a" is an array-of-arrays
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a = { { 100.0.rand }.dup(100) }.dup(100);
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// "b" is an equivalent Array2D, made using the "fromArray" class method
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b = Array2D.fromArray(100,100, a.flat);
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// Accessing
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a[15][22]
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b[15, 22]
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// Speed comparison 1: random access
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bench { 100.do(a[100.rand][100.rand]) }
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bench { 100.do(b[100.rand, 100.rand]) }
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// Speed comparison 2: iteration
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bench { 100.do(a.do { |row| row.do { |item| item * 2 } }) }
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bench { 100.do(b.do { |item| item * 2 }) }
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::
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]
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