Plots rose diagrams of circular data like wind speeds (P.W. Goedhart & R.W. Payne).
Options
PRINT = string token |
What to print (table); default * i.e. nothing |
|---|---|
SEGMENT = scalar |
Width of sectors (in degrees) into which to group an ANGLES variates before plotting; default 45 |
MSEGMENT = scalar |
Defines the centre (in degrees) of the sectors; default 0 |
INTERVALS = scalar or variate |
Scalar to define the intervals at which to summarize the data values, or a variate defining the boundaries between the intervals; default * i.e. determined automatically |
%INTERVAL = scalar |
Interval (on the percent scale) between the circles drawn to provide a scale on the diagram; default * i.e. determined automatically |
COLOURS = text or variate |
Colours to shade the triangles segment for each interval; default * sets suitable colours automatically |
SCREEN = string token |
Whether to clear screen before displaying the graphs (keep, clear); default clea |
Parameters
DATA = variates |
Data values |
|---|---|
ANGLES = factors or variates |
Directions of the data values |
TITLE = text |
Title for the graph; default * i.e. identifier of the DATA variate |
WINDOW = scalar |
Window for the graph; default 3 |
Description
WINDROSE plots data, like wind speeds, that are observed at angles around a circle. The data values are supplied in a variate by the DATA parameter. The angles at which the data values were observed are specified by ANGLES parameter. If this is set to a variate, WINDROSE groups the observations into sectors of width specified (in degrees) by the SEGMENT option, with centres defined by the MSEGMENT option. The sectors are centred at MSEGMENT, MSEGMENT+SEGMENT, MSEGMENT+2*SEGMENT, and so on. The default values for SEGMENT and MSEGMENT are 45 and 0 respectively. Alternatively, ANGLES can be set to a factor; its levels then define the midpoints of the sectors (and these must be in clockwise order).
WINDROSE categorizes the data values by determining the number of observations within a set of intervals specified by the INTERVALS option. The option can supply a variate specifying the lower boundaries of the intervals, or a scalar defining boundaries at multiples of the value that it contains. The diagram has a circular segment for each direction, with radius equal to the percentage of the total observations that are in that direction. To indicate the distribution of the data values in that direction, the segment is subdivided into a section for each interval. The sections are shaded in colours, which can be specified by the COLOURS option; ; by default, the standard colours are used in the same order as for pens 2, 3… (see PEN). Zero, negative or missing values of the DATA variate are assumed to represent “calm” values. These are represented by an empty circle at the centre of the diagram. Circles are drawn at intervals around this inner circle to provide a scale. The intervals between these circles are specified by the %INTERVAL option. You can also print the information, as a two-way table (directions × intervals) by setting option PRINT=table.
The parameters allow several rose diagrams to be plotted at once. The SCREEN option controls whether the existing screen is kept or cleared before plotting begins; by default SCREEN=clear. The WINDOW parameter specifies the graphics window in which each diagram is plotted. If these are not specified, the FFRAME procedure is used to set up a rectangular array with a window for each diagram. The TITLE parameter can be used to supply a title for each plot; if this is not specified, the identifier of the DATA variate is used.
Options: PRINT, SEGMENT, MSEGMENT, INTERVALS, %INTERVAL, COLOURS, SCREEN.
Parameters: DATA, ANGLES, TITLE, WINDOW.
Method
WINDROSE uses Genstat’s standard graphics and calculation commands.
Action with RESTRICT
If DATA or ANGLES are restricted, only the unrestricted units are used.
See also
Procedures: CASSOCIATION, CCOMPARE, CDESCRIBE, DCIRCULAR, DYPOLAR, GRIBIMPORT, RCIRCULAR.
Commands for: Graphics, Basic and nonparametric statistics.
Example
CAPTION 'WINDROSE example','Sulphur polution data'; STYLE=meta,plain
FACTOR [LABELS=!t(N,NE,E,SE,S,SW,W,NW); LEVELS=!(0,45...315)] WindDirection
& [LABELS=!t(no,yes); LEVELS=2] Rain
READ [SETNVALUES=yes] Sulphur,WindSpeed,WindDirection,Rain;\
FREPRESENTATION=labels
0 14.8 W no 13 14.3 N no 12 5.5 W no 22 5.0 NW no
12 4.5 W no 6 4.8 NE no 2 4.3 E no 24 4.0 SE no
36 9.3 S no 6 6.3 NE no 10 5.8 SW yes 4 8.3 W yes
3 16.0 SW yes 7 15.8 W no 2 16.0 SW yes 3 16.7 W yes
5 9.5 W no 6 9.8 W yes 13 12.0 W yes 49 4.8 N no
26 2.7 W no 6 6.5 SW no 3 13.5 SW yes 6 6.0 S yes
8 10.5 W yes 4 5.3 S no 6 18.0 S yes 5 8.5 W yes
3 15.0 SW yes 3 22.7 SW no 10 * * yes 7 8.5 NW no
3 8.3 SW no 1 14.3 SW no 4 15.0 SW no 5 10.5 S no
3 13.8 S no 3 8.5 S no 3 6.0 SE no 5 16.5 S yes
3 7.3 SE no 1 9.8 NE yes 6 7.3 NE yes 5 5.5 NE yes
5 6.0 E no 6 11.3 E no 11 8.8 E no 2 8.5 SE no
3 8.3 SE no 3 14.5 SE yes 2 9.0 S yes 3 11.5 S yes
7 10.0 SW no 3 11.3 SW no 3 18.5 SW yes 5 16.0 W no
29 8.3 W no 14 13.0 NW yes 15 13.5 NW no 9 10.0 NW no
17 9.0 NE no 4 7.3 N no 7 5.8 E no 14 8.5 SE no
4 6.0 SE yes 5 8.0 SW no 3 7.5 S yes 3 10.5 SW yes
4 11.0 SW yes 4 16.0 W no 2 13.5 SW yes 5 20.2 SW no
3 11.5 W yes 4 15.0 W no 5 10.3 SW yes 33 7.8 W yes
28 6.3 N yes 13 6.8 SW no 5 10.0 SE yes 26 5.5 SE no
4 17.0 N yes 8 19.2 N yes 9 10.0 NE yes 36 6.0 NE no
7 8.8 NW no 29 9.3 NE yes 11 6.5 W no 12 6.8 SW no
26 8.8 W no 21 8.3 NW no 13 5.3 E no 9 10.3 SW no
24 13.3 S yes 19 7.0 E yes 14 20.5 NE yes 28 17.5 NE no
20 14.8 NW yes 43 18.5 NW no 20 8.3 N no 25 0.5 N no
1 7.8 NW yes 16 3.5 E no 31 4.5 NW no 38 3.7 SE yes
11 8.0 W no 5 11.5 SW yes 5 5.8 S yes 4 14.8 SW no
14 13.3 S yes 3 10.8 S yes 3 15.0 SW yes 7 17.2 SW yes
2 12.0 SW no 2 18.0 SW yes :
WINDROSE [PRINT=table] Sulphur; ANGLES=WindDirection
& WindSpeed; ANGLES=WindDirection