Gallery of data displays


Welcome     Gallery     Handbook


Manual page for Gallery_of_data_displays(PL) Welcome to the ploticus gallery! Located here are dozens of graphical data displays produced using ploticus data display software. It is a mixture of simplistic and involved examples, intended both as an introduction/tutorial for getting started, and as a reference/test suite. Unless otherwise stated, all data are fictional.

You can download examples individually and try them. You can download the entire collection of examples by visiting the download page and downloading the "complete node". You can view tons of thumbnail examples in PNG or pseudo-GIF; there is also an alphabetical index of all ploticus examples.



Real-world examples



Clinical trials examples



Scaling and Axes

The preliminaries to plotting data.



Line Plots

Lineplots are used to show values that change from left to right. Often the change is over time along the X (horizontal) axis. Use proc lineplot.



Filled Line Plots

A line plot variant is to fill the area under the curve, in order to highlight a particular region, to show a difference between curves, or for stylistic reasons. Use proc lineplot with the fill option.



Range Sweeps

Range sweeps may be used to depict ranges that change from left to right. Often the change is over time along the X (horizontal) axis. Use proc rangesweep.



Pie Graphs

Pie graphs may be used to depict proportions that make up a whole, such as budget categories, or survey breakdowns. Use proc pie.



Bar Graphs (vertical)

Bar graphs (histograms) may be used to show comparisons, distributions, or category tabulations. They are also sometimes used to show values that change over time. Use proc bars.



Bar Graphs (horizontal)

Horizontal bars are useful for compactness or where time values are being compared. Use proc bars with the horizontalbars option.



Time Lines

Timelines are used to display events and durations with respect to time. The result may be in the form of a timetable, project progress chart, etc. Use proc bars with the horizontalbars and segmentfields attributes.



Bar Proportions

Bars may be used to show proportions. (A pie graph might also be used). Use proc bars with the stackfields option.



Scatter Plots (2-D)

Scatter plots display data points in one or two dimensions. Every data point is plotted with a mark, symbol, or label. 2-D scatterplots are often used to show correlation (or lack thereof) between two variables. Use proc scatterplot.



Scatter Plots (1-D)

1-D scatterplots show the distribution of one variable. Lines, symbols, characters or text may be used to mark points. Use proc scatterplot.



Range Bars (box plots)

Range bars (box plots) compactly show the distribution and range of a set of values. The median (50th percentile) is shown by a dot, the box covers the interquartile range (25th through 75th percentiles), and the tails show the minima/maxima or the 5th and 95th percentiles. Use proc rangebar which can compute the medians, quartiles, etc. as well as render the bars.



Error Bars

Error bars show the amount of margin of error for a value. This usually is +/- the standard deviation. If the amount of error has been calculated in advance, use proc bars. If you want ploticus to compute the mean and standard deviation, use proc rangebar with the meanmode option.



Curve Fitting

Curve fitting may be useful to illustrate trends in noisy data, or to show where data points lie with respect to average. proc curvefit can generate moving average and bspline curves.



Legends

When different symbols, colored bars, colored lines, etc. are used for comparison, a legend is usually necessary to describe what the various colors or symbols mean or what they correspond to. While not the most "sexy" element of a plot, it is often absolutely necessary. Use the legendlabel attribute of each plotting proc, then use proc legend to render the legend.



Annotation

Annotation may be used to denote specific points or regions on a plot that have some importance, or for any text placement. Use proc annotate.



Click map support

Clickmaps (image maps) allow the user to click with the mouse on an object or region in a graph as a hyperlink to a new web page.

A Note to Debian Users

Historically, the ploticus binary has been pl (not ploticus). This name is already used by another package in Debian, so the main binary has been renamed to ploticus. As I understand policy, addition of support for .gif, would consign the package to non-free. As .png is an adequate, if not perfect, substitute, I have chosen not to enable any gif support.

As pltab is being deprecated, I see no point in packaging it into the mainline Debian package. If you need pltab support, email me directly, and I will prepare a ploticus-pltab package for you. This package will never be officially released; it is intended only as a transitional tool for people who have used pltab in the past, and have data that would be awkward to switch to html format immediately.

You may find an occasional reference to plpng, which was an auxiliary program that is sometimes distributed with ploticus, depending on version and compilation options. Debian users do not need plpng. Simply use ploticus -png ... .

I have tried to change references to pl to ploticus, and expunge references to pltab, plpng, or plpngtab. Obviously, if these references are of a historical nature, refer to a package for another operating system, or are in an feedback email, it would be improper for changes to be made. If any remaining references to pl remain, simply read them as ploticus! This makes the Debian docuentation slightly different from the documentation available at ploticus.sourceforge.net. In event of any problems with this documentation, please use the Debian Bug Tracking System or contact me directly first, so that I can resolve any problems inadvertantly introduced.

James W. Penny


data display engine  
Copyright Steve Grubb


Markup created by unroff 1.0,    February 23, 2002.