| SAS/GRAPH Software: Reference |
SAS/GRAPH software
produces many kinds of charts, plots, and maps in both two- and three-dimensional
versions. In addition to helping you understand the variety of graphs that
are available to you, these descriptions will also help you choose the correct
type of graph for your data and point you to the appropriate chapter.
SAS/GRAPH software
uses the GCHART procedure to produce charts that graphically represent the
value of a statistic for one or more variables in a SAS data set. See The GCHART Procedure for a
complete description.
Block charts use three-dimensional blocks
to graphically represent values of statistics. Block charts are useful for
emphasizing relative magnitudes and differences among data
values.
![[IMAGE]](./images/01215095.gif)
Horizontal bar charts use horizontal bars to
represent
statistics based on the values of one or more variables. Horizontal bar charts
can generate a table of chart statistics and are useful for displaying exact
magnitudes and emphasizing differences.
![[IMAGE]](./images/01215096.gif)
Vertical bar charts use vertical bars to
represent statistics
based on the values of one or more variables. Vertical bar charts, which generate
only one statistic, are useful for displaying exact magnitudes and emphasizing
differences.
![[IMAGE]](./images/01215097.gif)
Pie charts, 3-D Pie charts, and Donut charts use the angle of pie slices to
graphically represent the value of a statistic for a data range. Pie charts
are useful for examining how the values of a variable contribute to the whole
and for comparing the values of several variables.
![[IMAGE]](./images/01215098.gif)
Star charts use the length of spines to
graphically represent the value of a statistic for a data range. Star charts
are useful for analyzing where data are out of
balance.
![[IMAGE]](./images/01215099.gif)
SAS/GRAPH
software uses
the GPLOT procedure to produce two-dimensional graphs that plot one or more
dependent variables against an independent variable within a set of coordinate
axes. GPLOT can display the data points as individual symbols (as in a scatter
plot), or use interpolation methods specified by the SYMBOL statement to join
the points, request spline interpolation or regression analysis, produce various
high-low plots, or generate several other types of plots.
GPLOT can also display data as bubble plots in which
circles of different sizes represent the values of a third variable.
Plots are useful for demonstrating the relationship
between two or more variables and frequently compare trends or data values
or depict movements of data values over time.
See The GPLOT Procedure
for a complete description.
Two-dimensional scatter plots
show the
relationship of one variable to another, often revealing concentrations or
trends in the data. Typically, each variable value on the horizontal axis
can have any number of corresponding values on the vertical
axis.
![[IMAGE]](./images/01215100.gif)
Simple line plots show the relationship of one variable
to another, often as movements or trends in the data over a period of time.
Typically, each variable value on the horizontal axis has only one corresponding
value on the vertical axis. The line connecting data points can be smoothed
using a variety of interpolation methods, including the Lagrange and the cubic
spline interpolation methods.
![[IMAGE]](./images/01215101.gif)
Regression plots specify that the plot is a regression
analysis. You can specify one of three types of regression equation --
linear, quadratic, or cubic -- and optionally display confidence limits
for mean predicted values or individual predicted
values.
![[IMAGE]](./images/01215102.gif)
High-low plots show how several values of one variable
relate to one value of another variable. Typically, each variable value on
the horizontal axis has several corresponding values on the vertical axis.
High-low plots include box, needle, and stock market
plots.
![[IMAGE]](./images/01215103.gif)
Bubble plots show the relative magnitude
of one variable in relation to two other variables. The values of two variables
determine the position of the bubble on the plot, and the value of a third
variable determines the size of the
bubble.
![[IMAGE]](./images/01215104.gif)
SAS/GRAPH software
uses the G3D procedure to produce three-dimensional surface and scatter plots
that examine the relationship among three variables. Variable values are plotted
on a set of three coordinate axes.
See The G3D Procedure
for a complete description.
Surface plots are three-dimensional plots that display
the relationship of three variables as a continuous surface. Surface plots
examine the three-dimensional shape of data.
![[IMAGE]](./images/01215105.gif)
Scatter plots enable you to examine
three-dimensional data points instead of surfaces and to classify your data
using size, color, shape, or a combination of these
features.
![[IMAGE]](./images/01215106.gif)
SAS/GRAPH software
uses the GCONTOUR procedure to examine three-dimensional data in two dimensions.
Lines or areas in a contour plot represent levels of magnitude (z)
corresponding to a position on a plane (x,y).
See The GCONTOUR Procedure
for a complete description.
Contour plots are two-dimensional plots that show three-dimensional
relationships. These plots use contour lines or patterns to represent levels
of magnitude of a contour variable plotted on the horizontal and vertical
axes.
![[IMAGE]](./images/01215107.gif)
When you need to interpolate or smooth data values that are
used by the G3D and GCONTOUR procedures, use the G3GRID procedure. The G3GRID
procedure does not produce graphics output but processes existing data sets
to create data sets that the G3D or GCONTOUR procedure can use to produce
three-dimensional surface or contour plots. See The G3GRID Procedure for a complete description.
SAS/GRAPH software
uses the GMAP procedure to produce two- and three-dimensional maps that can
show an area or represent values of response variables for subareas.
SAS/GRAPH software
includes data sets to produce geographic maps. In addition, you can create
your own map data sets.
See The GMAP Procedure
for a complete description.
Block maps are three-dimensional maps that represent
data values as blocks of varying height rising from the middle of the map
areas.
![[IMAGE]](./images/01215108.gif)
Choropleth maps are two-dimensional maps that display
data values by filling map areas with combinations of patterns and color that
represent the data values.
![[IMAGE]](./images/01215109.gif)
Prism maps are three-dimensional maps that display data
by raising the map areas and filling them with combinations of patterns and
colors.
![[IMAGE]](./images/01215110.gif)
Surface maps are three-dimensional maps that represent
data values as spikes of varying heights.
![[IMAGE]](./images/01215111.gif)
SAS/GRAPH software
also provides several utility procedures for handling map data.
The GPROJECT procedure lets you choose
how geographic maps are
projected. This is particularly important for large areas because producing
a map of any large area on the Earth involves distorting some areas in the
process of projecting the spherical surface of the Earth onto a flat plane.
You can use the procedure to select the projection method that least distorts
your map.
Map areas are constructed of joined data points. Each
data point represents an observation in a SAS data set. For large maps, the
amount of data can be prohibitively expensive (in terms of computing resources
or time to process); the GREDUCE procedure enables you to reduce the number
of points in the data set. The GREMOVE procedure enables you to remove boundary
lines within a map.
You can use SAS/GRAPH software
to create slide presentations of your graphs. With SAS/GRAPH you
can
Use the GSLIDE procedure to create text slides in which you
can specify a variety of colors, fonts, sizes, angles, overlays, and other
modifications as well as drawing lines and boxes on the output.
See The GSLIDE Procedure
for a complete description.
Text slides display text as graphics output. Text slides
can be used as title slides for presentations, or to produce certificates,
signs, or other display
text.
![[IMAGE]](./images/01215112.gif)
Use the GPRINT procedure to display as a graphic SAS procedure output that
has been saved in a text file. With GPRINT, you bring the text file into SAS/GRAPH and
then add titles, notes, and footnotes, and select colors for the output.
See The GPRINT Procedure
for a complete description.
Use the GREPLAY procedure to combine
several graphs into
a single output. You can create special effects by overlaying or rotating
the graphs at any angle.
Templated graphs display two or more graphs or text slides as one output by
replaying stored graphs into a template or framework. Like graphs and text
slides, templated graphs can be ordered in groups and stored in catalogs for
replay as part of a presentation.
Templated graphs
![[IMAGE]](./images/01215113.gif)
In addition, you can use the
GREPLAY procedure to create
an automated or user-controlled presentation of graphics output. The GREPLAY
procedure enables you to name, arrange, and customize the presentation of
graphs that are stored in a catalog.
See The GREPLAY Procedure
for a complete description.
You also can use global
statements and graphics options in SAS/GRAPH programs.
With global statements, you can add titles and footnotes and control the
appearance of axes, symbols, patterns, and legends. With graphics options,
you can control the appearance of graphics elements by specifying default
colors, fill patterns, fonts, text height, and so on.
The Annotate facility enables you
to program
graphics by using certain variables in SAS data sets. It is often used to
add text or special elements to the graphics output of other procedures, although
it also can be used to construct custom graphics output. Text and graphics
can be placed at coordinates derived from input data, as well as coordinates
expressed as explicit locations on the display.
Annotated graphs
![[IMAGE]](./images/01215114.gif)
The Annotate facility
can also be used to generate custom graphics
without using any of the SAS/GRAPH graphing
procedures.
The DATA
Step Graphics Interface provides functions and calls that produce graphics
output from the DATA step, rather than from a procedure. The functions and
calls are similar in form to those specified by the ISO Graphic Kernal Standard
(GKS); however, the interface is not an implementation of the GKS. The form
is similar enough that many GKS-compliant programs may be converted easily
to run as SAS/GRAPH programs.
To generate presentation graphs without writing any SAS/GRAPH
code, you can use the experimental application Graph-N-Go. To start Graph-N-Go,
submit the following from the SAS command line:
af c=sashelp.gng.gng.scl
For information on using Graph-N-Go, see the application's Help.
Graph-N-Go is experimental in Version 7, which means that it has not
completed a formal testing cycle and is, therefore, not supported by SAS Institute.
Nevertheless, it is a stable application that you can use to generate presentation
graphs.
Copyright © 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.
