| Processing Variables with Arrays |
| Expanding Your Use of
Arrays |
| Creating Variables with the ARRAY Statement
So far, you have learned several ways to reference existing variables using an ARRAY statement. You can also create variables using an ARRAY statement. |
SAS Data Set Hrd.Convert
Name
Weight1
Weight2
Weight3
Weight4
Weight5
Weight6
Alicia
153.4
151.9
151.7
148.6
145.5
145.9
Betsy
116.0
116.0
114.0
111.1
109.8
108.2
Brenda
151.2
149.0
147.7
146.4
145.1
143.7
Carl
149.0
146.8
145.5
144.2
142.9
141.5
Carmela
140.2
137.8
136.5
135.4
134.0
128.3
Assume you need to calculate the weight gain or loss from week to week
for each member of a fitness class, shown above. You'd like to create variables
that contain this weekly difference. To perform the calculation, you first
group the variables Weight1 through Weight6 into
an array.
data hrd.diff;
set hrd.convert;
array wt(6) weight1-weight6;
An additional ARRAY statement enables you to create the new variables. For this example, you need five variables to store the differences between the six recorded weights. data hrd.diff;
set hrd.convert;
array wt(6) weight1-weight6;
array WgtDiff(5);
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SAS Data Set Hrd.Convert
Name
Weight1
Weight2
Weight3
Weight4
Weight5
Weight6
Alicia
153.4
<-1->151.9
<-2->151.7
<-3->148.6
<-4->145.5
<-5->145.9
Betsy
116.0
116.0
114.0
111.1
109.8
108.2
Brenda
151.2
149.0
147.7
146.4
145.1
143.7
Carl
149.0
146.8
145.5
144.2
142.9
141.5
Carmela
140.2
137.8
136.5
135.4
134.0
128.3
When creating variables with an ARRAY statement, you do not need to specify
array elements. Because you are not referencing existing variables, SAS software
automatically creates the variables for you.
array WgtDiff(5); |
| Arrays of Character Variables
To create an array of character variables, add a dollar sign ($) after the array dimension. array firstname(5) $; By default, all character variables created with an ARRAY statement are assigned a length of 8. You can assign your own length by specifying the length after the dollar sign. array firstname(5) $ 24; The length you specify is automatically assigned to all variables created by the ARRAY statement. |
| Default Variable Names
The default variable names are created by concatenating the array name and the numbers 1, 2, 3, and so on, up to the array dimension. array WgtDiff(5);
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
WgtDiff1 WgtDiff2 WgtDiff3 WgtDiff4 WgtDiff5
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If you prefer, you can specify individual variable names.
To specify variable names, you list each name as an element of the array.
The following ARRAY statement creates the numeric variables
Oct12, Oct19, Oct26,
Nov02, and Nov09. |
array WgtDiff(5) Oct12 Oct19 Oct26 Nov02 Nov09;
array WgtDiff(5);
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
Oct12 Oct19 Oct26 Nov02 Nov09
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Copyright © 2002 SAS Institute Inc.,
Cary, NC, USA. All rights reserved.