GROUP LABEL

GROUP LABEL (LET)

Subcommand under LET

Converts previously read character data, literal text strings, or previously defined strings to group labels.

Dataplot can now read character data using the
SET CONVERT CHARACTER ON

command. This command stores the character fields in the file "dpchzf.dat".

The two primary uses of character data are:

1. Provide a row identifier for the data.

2. Define a group (or factor) variable. For example, we can identify sex by coding males as M and females as F.

In the context of Dataplot, we can use groups in two contexts.

1. The group variable can be used in a numerical context. For example,
   BOX PLOT Y X

   Here, X is the group-id variable.

   The command CHARACTER CODE (or ALPHABETIC CHARACTER CODE) can be used to create a coded numeric variable from a character variable saved in the file dpchzf.dat.

2. We may want to use the group label for labeling. In this case, we typically want to use the character coding.

   The GROUP LABEL command is used to create character group labels from a character variable saved in the file dpchzf.dat.

   The GROUP LABEL will extract and save the unique rows for the specified character variable.

   As of version 1/2004, Dataplot can use the group labels for the tic mark labels on a plot. Enter

   HELP TIC MARK LABEL FORMAT
   HELP TIC MARK LABEL CONTENT
   

   for details. We anticipate additional uses of group labels in subsequent releases of Dataplot.

LET <ig> = GROUP LABEL <ix>
where <ix> specifies the name of the character variable in the file dpzchf.dat;
and    <ig> specifies the name for the group label variable.

The character variable is originally created with a READ command where the SET CONVERT CHARACTER ON was entered prior to the READ.

LET <ig> = GROUP LABEL <str1> .... <strk>
where <str1> ... <strk> denote k literal text strings.

This syntax can be used to define a group label variable by entering explicit text strings. Each string is separated by one or more spaces. If the text string contains a space, enter the space as SP() since in this context, quotes are not used to delineate the strings (a quote will simply be considered part of the text string).

LET <ig> = GROUP LABEL <str1> .... <strk>
where <str1> ... <strk> denote k previously defined strings.

This syntax can be used to define a group label variable based on previously defined strings. Note that this syntax supports the TO clause. That is,

LET IG = GROUP LABEL S1 TO S5

will create the group label variable from the previously defined strings S1, S2, S3, S4, and S5.

Note that if any of the names listed are not previously defined strings, then all of the names will be interpreted as literal text (i.e., Syntax 2).

SET CONVERT CHARACTER ON
READ TEST.DAT Y X IX
LET IG = GROUP LABEL IX


LET IG = GROUP LABEL CASESP()1 CASESP()2 CASESP()3


LET STRING S1 = Case 1
LET STRING S2 = Case 2
LET STRING S3 = Case 3
LET STRING S4 = Case 4
LET STRING S5 = Case 5
LET IG = GROUP LABEL S1 TO S5

Dataplot allows a maximum of five group label variables. You may reuse a group label variable by using the name of a previously entered group label.

The maximum number of levels for a given group is MAXOBV/100 with MAXOBV denoting the maximum number of observations for a variable (this is typically set to either 100,000 or 20,000).

The SORT BY <statistic> command can be used to generate sorted plots. This command returns an index variable that can be used to conveniently sort the tick mark labels created using the GROUP LABEL command. Enter HELP SORT BY for details.

None

None

READ	= Carries out a column-wise input of data.
CONVERT CHARACTER	= Specify how Dataplot will handle character data.
CHARACTER CODE	= Converts character data to a coded numeric variable.
ALPHABETIC CHARACTER CODE	= Converts character data to a coded numeric variable.
ROW LABELS	= Define row labels from character data.
SORT BY	= Sort a response variable and a group-id variable by a statistic.
TIC MARK LABEL FORMAT	= Specify the format for tick mark labels.
TIC MARK LABEL CONTENT	= Specify the content for alphabetic tick mark labels.

Input/Output, Presentation Graphics

2004/1
2006/1: Added Syntax 2 and Syntax 3 versions of the command

 
set convert character on
skip 25
read draft69c.dat rank day month
.
let ig = group label month
x1tic mark label format group label
x1tic mark label content ig
x1tic mark label font simplex
x1tic mark label angle 45
x1tic mark label displacement 10
let xcode = character code month
.
major xtic mark number 12
minor xtic mark number 0
xlimits 1 12
xtic offset 0.5 0.5
.
char box plot
line box plot
fences on
.
box plot rank xcode