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如何在Smalltalk中管理2d阵列?

visualworks multidimensional-array smalltalk

4

Serty Oan · 技术社区 · 15 年前

我有一个点列表,必须做腐蚀/扩张手术。我需要一种2d数组,但在VisualWorks中找不到该怎么做(我知道Squeak中有一个Array2d类,但我必须使用VW)。

4 回复 | 直到 15 年前

1

3

Janko MivÅ¡ek 15 年前

简单地使用一种通用方法:数组:

(Array new: xSize)
    at: 1 put: ((Array new: ySize) at: 1 put: aValue; at: 2 put: aValue; ...);
    at: 2 put: ((Array new: ySize) at: 1 put: aValue; at: 2 put: aValue; ...);
    ...

2

4

Paolo Bonzini 15 年前

许多Smalltalk实现都会有某种矩阵类,有时会进行优化,这些类会有一些方法,例如#rowAt:columnAt:(或者为了简洁起见#at:at:)。

3

2

Alan Wostenberg 15 年前

如果您想使操作更高效,请学习VisualWorks图像类、协议“图像处理”和“位处理”。在原语的基础上建立你自己的侵蚀/扩张操作。

4

2

Tobias 10 年前

test := Matrix new: 3.     "this defines a 3 x 3 array"
test at: 1 at: 1 put: 5.
test at: 1 at: 2 put: 6.
test at: 1 at: 3 put: 7.

等等,等等,你只能这样做二维数组,它们必须是一个方阵。我和我儿子正在做一个数独游戏ymmv,这个项目做得很好。干杯!

5

0

David Oznot 4 年前

Array subclass: Array2Dâ¨
instanceVariableNames: 'myRows myColumns'â¨
classVariableNames: ''
poolDictionaries: ''â¨
category: 'Basic Data Structures'

"I am a two-dimensional array of arbitrary objects.

[Privately, I am really a linear (one-dimensional) array.
I locate my elements internally by index arithmetic on their
(two-dimensional) coordinates.]"


Instance creation (class)
-------------------------

new: nRows by: nColumns
   "Create a new instance of me with nRows rows and nColumns
    columns."
   
   ^(super new: (nRows * nColumns))
       withRows: nRows withColumns: nColumns
   
   "exampleArray := Array2D new: 10 by: 5"


Initialization
--------------

withRows: nRows withColumns: nColumns
   "Set my number of rows and columns to nRows and nColumns,
   respectively.â¨"
   
   myRows    := nRows.
   myColumns := nColumns


Properties
----------

rows
   "My number of rows."
   
   ^myRows


columns
   "My number of columns."
   
   ^myColumns


Element access
--------------

atRow: whichRow atColumn: whichColumn
   "My element at row whichRow and column whichColumn."
   
   ^super at: (self indexAtRow: whichRow
                      atColumn: whichColumn)
   
   "exampleValue := exampleArray atRow: 6 atColumn: 4"


atRow: whichRow atColumn: whichColumn put: newValue
   "Store value newValue as my element at row whichRow and
    column whichColumn."
   
   super at: (self indexAtRow: whichRow
                     atColumn: whichColumn)
        put: newValue
   
   "exampleArray atRow: 6 atColumn: 4 put: exampleValue"


Private
-------

indexAtRow: whichRow atColumn: whichColumn
   "The internal index at which I store my element at row
    whichRow and column whichColumn.â¨"
   
   ^((whichRow - 1) * myColumns) + whichColumn