4 New Ways to Use Array Notation: Initializing Multi-Dimensional Arrays

par Janet Albers | Mis à jour le : 06/10/2015 | Commentaires : 0

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OS 28

Initializing variables within an array is more flexible than ever with OS 28 (CR6 OS 1). You can think of a single dimensioned array as numbers in a column. Two dimensions, in comparison, puts numbers in rows and columns. The third dimension is a page.

For example:

Public A(3) 'A(column)
Public B(3,2) 'B(row, column)
Public C(2,3,4) 'C(page, row, column) Not used in this example

Before the release of the new OS, you could initialize the variables as you declared them.

For example:

Public Ai(3) = {1,1,1} 'initialize single dimensioned array
Public Bi(2,2) = {10,20,30,40}	'Bi(1,1)=10, Bi(1,2)=20
				'Bi(2,1)=30, Bi(2,2)=40

To use the new capability of OS 28 (CR6 OS 01) most effectively, there are some rules you should understand:

  • An empty set of parentheses designates an array-assigned expression. For example, reference array() or array(A,B,C)().
  • Only one dimension of the array is operated on at a time.
  • To select the dimension to be operated on, negate the dimension of index of interest. For example, to operate on the dimension “B,” the syntax is array(A,-B,C).

The example program below initializes the variables A(3) and B(3,2) as declared above:

'Main Program
	Scan (1,Sec,0,0)
		A()=1 ' all values = 1
		'Initialize B(3,2) as follows:
		'100	100
		'200	300
		'200	300
		B(1,-1)() = 100 'set B(1,1) and B(1,2) to 100
		B(-2,1)() = 200 'set B(2,1) and B(3,1) to 200
		B(-2,2)() = 300 'set B(2,2) and B(3,2) to 300

Note: This new syntax does not affect how repetitions within instructions write to, or read from, variable arrays. To see how to use array notation and repetitions within measurement instructions, watch the CRBasic | Advanced Programming video.

Tip: After updating your operating system, it’s a good idea to check your existing programs to ensure they continue to run as expected.

For more information about, and examples of, multi-dimensional arrays, we have several resources to help you. You can search for the section in your data logger manual titled “Array-Assigned Expression.” The CRBasic Editor Help application in LoggerNet is also a good resource. For example, search for “multi-dimensional arrays”:

Multi-dimensional arrays

Recommended for You: To learn more about OS 28, review the “Powerful New Operating System for CR800, CR1000, CR3000” newsletter article.

Campbell Scientific’s newest data logger operating system (OS 28 for the CR800CR1000, and CR3000; OS 01 for the CR6 datalogger) enables you to use Array Notation in CRBasic multi-dimensional arrays in new ways. This article explored one of these methods—initializing multi-dimensional arrays. Another method, simple scaling, was discussed in the first article in this series. Two other methods, complex scaling and copying or transposing, will be discussed in articles to follow.

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A propos de l'auteur

janet albers Janet Albers est rédactrice technique senior. Elle vous fera part de ses conseils, simplifiera les concepts et vous guidera vers un projet réussi. Elle est à Campbell Scientific, Inc depuis plus longtemps que la CR1000, mais pas depuis aussi longtemps que la CR10X. Après les heures de travail, Janet aime le plein air avec ses garçons et ses chiens.

Voir tous les articles de cet auteur.


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