Displays spider-web and star plots (W. van den Berg).
Options
METHOD = string token |
Type of plot (spiderweb, star); default spid |
|---|---|
MARKS = scalar or variate |
Distances between the stands of the web or marks on the axes of the star (scalar), or positions of those strands or marks (variate); default 0.25 |
ANGLE = scalar |
Angle to rotate the plot, in degrees; default 0 |
SIZEMULTIPLIER = scalar |
Controls the size of the labels identifying the categories; default selects a size appropriate to the number of plots in the frame |
FRAMESHAPE = string token |
Shape of the plotting frame (landscape, portrait, square); default squa |
Parameters
DATA = tables |
Values to plot in each frame |
|---|---|
CATEGORIES = factors |
Factor specifying the categories that define the axes in the plots |
GROUPS = factors or pointers |
Factor specifying the groups to appear in each plot |
TRELLISGROUPS = factors or pointers |
Factor or factors specifying the different plots of a trellis plot of a multi-way table |
PAGEGROUPS = factors or pointers |
Factor or factors specifying plots to be displayed on different pages |
TITLE = texts |
Title for the graph; default none |
COLOURS = texts or variates |
Colours to be used for the groups |
Description
A spider-web or a star plot can be used to display information on several categories observed on an individual. The categories are represented as equally-spaced radii from a common origin. The observations for the individual along each radius are joined by straight lines to form a polygon, whose shape can then be used to identify individuals with similar characteristics. The spider-web plot differs from the star plot, in that it also contains reference lines joining the radii (much like a real spider’s web). In a star plot, there are still markings on the radii, but these are not joined together. Spider-web plots are produced by default, but you can set option METHOD=star to produce star plots instead.
The observations must be supplied in a table, specified by the DATA parameter. The table must be classified by a factor to identify the categories. This must be specified by the CATEGORIES parameter.
You can use the GROUPS parameter to plot information from more than one individual in the same plot. This can specify either a factor, or a pointer containing several factors, each of whose levels (or combination of levels) provides data from one of the individuals. These factors must again be among the factors classifying the DATA table. Similarly the TRELLISGROUPS and PAGEGROUPS parameters allow you to define different plots to appear in a trellis arrangement or on different pages. At least one of GROUPS, TRELLISGROUPS and PAGEGROUPS must be set.
The TITLE parameter can supply a title for the plots, and the COLOURS parameter can supply either a text or a variate to define the colours to be used for the groups.
The MARKS option can supply either a scalar to define the distance between each pair of marks or pair of reference lines on the radii, or a variate to define their actual positions. The values must be between zero and one, as the DATA values are standardized to that range for the plot. The ANGLE option can specify an angle by which the plots are to be rotated (default 0).
The SIZEMULTIPLIER option allows you to control the sizes of the labels that are plotted at the ends of the radii to identify the categories. By default, the size is set automatically, according to the number of plots in the frame.
The FRAMESHAPE option specifies the shape of the frame, with settings:
landscape |
for a frame of size 1.4 × 1.0 i.e. wider in the x- than the y-direction, |
portrait |
for a frame of size 1.0 × 1.4 i.e. wider in the y- than the x-direction, |
square |
for a frame of size 1.0 × 1.0. |
Some graphics devices do not support the use of device cordinates greater than 1.0, so the default is FRAMESHAPE=square. (See FRAME and DEVICE for more information.) There must be no more than 36 plots in a square frame. Landscape and portrait frames can hold up to 48.
Options: METHOD, MARKS, ANGLE, SIZEMULTIPLIER, FRAMESHAPE.
Parameters: DATA, CATEGORIES, GROUPS, TRELLISGROUPS, PAGEGROUPS, TITLE, COLOURS.
See also
Directive: DHISTOGRAM.
Procedure: DTABLE.
Commands for: Graphics.
Example
CAPTION 'DSPIDERWEB example'; STYLE=meta
TEXT [VALUES=Engcc,Ncyl,Tankl,Weight,Length, \
Width,Height,Wbase,Tspeed,Stst] Catname
FACTOR [LABELS=Catname] Category
TEXT [VALUES=Estate,'Arna1.5','Alfa2.5',Mondialqc,\
Testarossa,Croma,Panda,Regatta,Regattad,Uno,\
X19,Contach,Delta,Thema,Y10,Spider] Carname
FACTOR [LABELS=Carname] Car
TABLE [CLASS=Car,Category] Attributes
READ Attributes
1490 4 50 966 414 161 133 245 177 10.9
1409 4 50 845 399 162 139 242 174 10.2
2492 6 49 1160 433 163 140 251 210 8.2
3185 8 87 1430 458 179 126 265 249 7.4
4942 12 120 1506 449 198 113 255 291 5.8
1995 4 70 1180 450 176 143 266 209 7.8
965 4 35 761 338 149 146 216 134 16.8
1585 4 55 970 426 165 141 244 180 10.0
1714 4 55 980 426 165 141 245 150 18.9
999 4 42 720 364 155 143 236 145 16.2
1498 4 48 912 397 157 118 220 171 11.0
5167 12 120 1446 414 200 107 245 286 4.9
1585 4 45 1000 389 162 138 247 195 8.2
1995 4 70 1150 459 175 143 266 224 7.6
1049 4 47 790 339 151 143 216 179 11.8
1995 4 45 1050 414 162 125 228 190 9.0 :
DSPIDERWEB Attributes; CATEGORIES=Category; TRELLISGROUPS=Car