VARIABLE WIDTH BAR PLOT

VARIABLE WIDTH BAR PLOT

Graphics Command

Generates a variable width bar plot.

The basic bar plot is based on a single response variable that controls the height of the bar (basic bar plots are generated with Dataplot by using the PLOT command with appropriate settings for the BAR and related attribute setting commands for the bars). The variable width bar plot adds a second response variable that controls the width of the bars.

Optionally, an additional tag variable can be specified. Rows that have the same value for the tag variable will use the same attributes for the bars. The lowest value of the tag variable will use the first setting of the BAR attribute commands, the second lowest value will use the second setting of the BAR attribute commands and so on. This is most typically used to control the color of the bars. If no tag variable is specified, then all bars will be drawn with the same attributes.

VARIABLE WIDTH BAR PLOT <y1> <y2>
                        <SUBSET/EXCEPT/FOR qualification>
where <y1> is the variable that controls the height of the bar;
            <y2> is the variable that controls the width of the bar;
and where the <SUBSET/EXCEPT/FOR qualification> is optional.

With this syntax, all bars will be drawn with the same attributes. The <y1> and <y2> variables must have the same number of observations.

VARIABLE WIDTH BAR PLOT <y1> <y2> <tag>
                        <SUBSET/EXCEPT/FOR qualification>
where <y1> is the variable that controls the height of the bar;
            <y2> is the variable that controls the width of the bar;
            <tag> is a variable that specifies which bars are drawn with the same attributes; and where the <SUBSET/EXCEPT/FOR qualification> is optional.

With this syntax, bars that have the same value for the <tag> variable will be drawn with the same attributes. Most typically, this is used to specify the fill color for the bars. The <y1>, <y2> and <tag> variables must have the same number of observations.

The use of the <tag> variable is demonstrated in the Program example below.

VARIABLE WIDTH BAR PLOT Y1 Y2
VARIABLE WIDTH BAR PLOT Y1 Y2 TAG
VARIABLE WIDTH BAR PLOT Y1 Y2 SUBSET Y2 > 0

Dataplot provides two options for the bar widths.
1. In the first option, the bar width is set to 1 for the maximum value of the second response variable. The remaining bar widths are set proportional to this maximum width. For example, if the maximum value for the second response variable is 20, a value of 5 for the second response variable would result in a bar width of 5/20 (= 0.25). With this option the bars are not connected. The advantage of this method is that it is easier to make the axis labels legible.

2. In the second option, the total width is calculated as the sum of the values in the second response variable plus one. Then the individual bar widths are set to proportional to the total width. So if the total width is 100 and a given value of the second response variable is 30, the bar width for that observation will be 30/100 (= 0.3). With this option, the bars are connected. This option may be preferred when there are a large number of response values.

To set this option, enter the command

SET VARIABLE WIDTH BAR PLOT CONNECTED <ON/OFF>

The default is OFF (i.e., option 1).

SET VARIABLE WIDTH BAR PLOT CONNECTED OFF

VARIABLE WIDTH BAR CHART

PLOT	=	Generates a data or function plot.
WATERFALL PLOT	=	Generate a waterfall plot.
BULLET PLOT	=	Generate a bullet plot.
FLUCTUATION PLOT	=	Generate a fluctuation plot.
BAR	=	Sets the type for plot bars.
BAR FILL	=	Sets the fill option for plot bars.
BAR FILL COLOR	=	Sets the color the fill region for plot bars.

Presentation Graphics

2025/06

 
skip 25
column limits 1 29
read subject.dat number perwomen type
skip 0
let n = size number
column limits 30 80
loop for k = 1 1 n
    let irow = 25 + k
    row limits irow irow
    read string subject.dat  subj^k
end of loop
column limits
row limits
let ig = group label subj1 to subj^n
.
. Step 2:   Set some plot control
.
case asis
title case asis
label case asis
tic mark label case asis
.
horizontal switch on
ylimits 1 n
major y1tic mark number n
minor y1tic mark number 0
tic mark offset units data
y1tic mark offset 0.8 0.8
y1tic mark label format group label
y1tic mark label content ig
y1label Subject
y1label displacement 21
.
x1limits 0  15000
x1label Number of Entrants
x2label Width of Bar: Percentage of Women
x3label Blue: Theoretical Subject, Red: Vocational Subject
.
frame corner coordinate 25 20 95 90
title Variable Width Bar Chart
bar fill color blue red
.
. Step 3:   Generate the plot
.
set variable width bar plot connected off
variable width bar plot number perwomen type
.
. Step 4:   Now generate with "connected" option ON
.
ylimits 1 n
major y1tic mark number n
minor y1tic mark number 0
tic mark offset units data
y1tic mark offset 1.0 2.2
y1tic marks off
y1tic mark labels off
.
set variable width bar plot connected on
variable width bar plot number perwomen type
    

.
.           Now generate the y-axis tic mark labels
.
justification rice
let xcoor = 23
.
loop for k = 1 1 n
    let ycoor = xplot(k)
    movesd xcoor ycoor
    text ^subj^k
end of loop