-hplot- and -hbar- for presentation graphics
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Speakers |
Nicholas J. Cox, Durham University, UK
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hplot and hbar are basic presentation graphics programs using
gph. Stata 6 is required. Driver programs have been written for
hplot and hbar automating various common tasks: cihplot
shows confidence intervals (calls up ci), tabhplot and
tabhbar display one- or two-dimensional tables of frequencies in
graph form (counting is done internally), and hbox uses hbar
to provide an alternative to graph, box. They are all downloadable
from the SSC-IDEAS archive.
hplot, for horizontally labelled plots, shows one horizontal line for
each observation included with one or more point symbols using a common
scale. It can produce a variety of plots, including
- W.S. Cleveland's dot charts or dot plots
- variations on them with continuous lines
- D.R. McNeil's horizontal parallel line plots
- displays of key quantities with/without confidence intervals
By default, data are on dotted lines with base zero that extend to the
maximum for each observation. If negative values are present, such dotted
lines also extend to the minimum for each observation.
If grid option: horizontal dotted lines extend over whole data
region.
If line option: horizontal continuous lines with base at
left-hand margin.
If range option: horizontal dotted or
continuous lines extend only over range of values for each observation.
If data allow, a different base may be forced using xscale().
The legend on left can be from a specified variable: it is right-justified
and should look readable up to about 30 observations.
The user can force extra gaps between lines and tune magnitude of those
gaps. Extra legends may be inserted in such gaps.
The order of lines can be controlled by sorting on any variable(s).
The standard symbol set of graph has been extended to include
vertical bars, arrows, and crosses.
The large title() may be put at the top of the graph.
The user may control font sizes.
hbar for horizontal bar charts has many of the same features as
hplot.
Bars for different variables stacked with base at 0: optionally, bars may be
horizontal lines with or without vertical lines at either or both ends.
The shading set of graph has been extended to include empty
(unshaded) and invisible bars.
The user can tune the fraction of vertical space taken up by bars (1 means
bars touch).
Values may also be shown as text, either inside or outside bars.
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