summaryrefslogtreecommitdiff
path: root/graphics/pstricks/contrib/pst-bar/pst-bar-doc.tex
blob: 74fb0702381cf249a78c91381bbecc92e056c4a5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
%% $Id: pst-bar-doc.tex 63 2008-11-26 18:00:46Z herbert $
\documentclass[11pt,english,BCOR10mm,DIV12,bibliography=totoc,parskip=false,smallheadings
    headexclude,footexclude,oneside]{pst-doc}
\listfiles
\usepackage{pst-bar}%
\let\pstBarVersion\fileversion
\usepackage{booktabs}%
\usepackage{filecontents}%
\usepackage{verbatim}%
\makeatletter
\def\kernhack#1#2{%
    \begingroup
	\setbox\z@\hbox{#1#2}%
	\dimen@\wd\z@
	\setbox\z@\hbox{#1{}#2}\advance\dimen@-\wd\z@
	\ifdim\dimen@=\z@\else\kern\dimen@\fi
    \endgroup
}
\def\switch#1#2{%
    \begingroup
	\def\@switch##1#1##2\@nil#1##3\@stop{%
	    \def\reserved@a{##3}%
	    \ifx\reserved@a\@empty#2\else
		\setbox\z@\hbox{##1#1}%
		\setbox\tw@\hbox{\kernhack{#1}{##2}\switch{#1}{##2}}%
		\dimen@\wd\tw@\advance\dimen@\wd\z@%
		\wd\z@\dimen@%
		\rlap{\hb@xt@\dimen@{\hfil\unhbox\tw@}}%
		\box\z@
	    \fi
	}%
	\@switch#2\@nil#1\@nil#1\@stop
    \endgroup
}
% Given an e-mail address of the form abc@def.ghi.jkl, reverses it to be jkl
% ghi. def. abc@
\def\switchemail#1{\expandafter\@switchemail#1\@stop}
% Helper function for \switchemail. Note the \copy, because \kernhack will
% destroy the box otherwise. Need to do some funky stuff because of catcodes.
\begingroup
\makeatother
\def\tmp#1#2#3{%
    \gdef#1##1@##2#2{%
	\begingroup
	\setbox#3\hbox{\switch{.}{##2}}%
	\switch{@}{##1@\copy#3}%
	\endgroup
    }%
}
\makeatletter
\tmp\@switchemail\@stop\@tempboxa
\endgroup
\makeatother

\usepackage[T1]{fontenc}%

\begin{filecontents*}{example1.csv}
    Set 1, Set 2, Set 3
    1, 2, 3
    1, 2, 3
\end{filecontents*}

\begin{filecontents*}{example2.csv}
    Set 1, Set 2, Set 3
    1, 2, 3
    0.5, 1.5, 1
\end{filecontents*}

\begin{filecontents*}{example3.csv}
    Set 1, Set 2, Set 3
    1, 2, 3
    0.5, 1.5, 1
    0.75, 1.6, 0.9
    0.9, 2.2, 2.5
\end{filecontents*}

\begin{filecontents*}{example4.csv}
    Set 1, Set 2, Set 3
    1, 0, 3
\end{filecontents*}

\begin{filecontents*}{example5.csv}
    0, 2, 0
\end{filecontents*}

\begin{filecontents*}{example6.csv}
    Set 1, Set 2, Set 3
    1.3, 2.5, 0.9
\end{filecontents*}

\begin{filecontents*}{example7.csv}
    0.7, 1.9, 0.4
    1.2, 2.7, 1.4
\end{filecontents*}

\begin{document}
\title{\texttt{pst-bar}\\ Bar charts for \texttt{pstricks}\\
    {\small v.\pstBarVersion}}
\author{Alan Ristow}
\docauthor{Alan Ristow\\Herbert Vo\ss}
\date{\today}
\maketitle

  \begin{abstract}
    With \LPack{pst-bar}, one may use \LPack{pstricks} to produce bar charts
    directly from a data file. This package is still in the beta stage --- the
    usual caveats pertaining to beta software apply. Additional features and
    improved (in both content and layout) documentation will be provided as the
    code stabilizes.
  \end{abstract}

\section{Introduction}
    \LPack{pst-bar} uses the power and flexibility of
    \LPack{pstricks}~\cite{vanzandt:93} to draw bar charts from data stored in a
    comma-delimited file. Several solutions exist for drawing bar charts for
    \TeX\ and \LaTeX\ documents. The obvious solution is to use an external
    program, such as \Index{gnuplot} or \Index{Matlab}, that can save bar charts in a format
    that may be read directly into \TeX\ or \LaTeX. This approach has the
    disadvantage that extra effort is required to produce charts with a uniform
    appearance that blend well with the other graphics in a document. In many
    cases the text in the chart can be typeset by \LaTeX\ with the aid of the
    \LPack{psfrag} or \verb|psfragx| packages (for diagrams created with Matlab,
    this process can be accelerated by \Index{LaPrint}, a Matlab program written
    specifically for this purpose~\cite{linneman:04}). However, some programs
    write the text elements in Encapsulated Postscript files in such a way that
    the \LPack{psfrag}-based options cannot work.

    Bar charts may also be drawn using the built-in drawing tools provided by
    \TeX\ and \LaTeX. This is the approach used by the \LPack{histogr}
    package~\cite{schopf:97}, which is intended to draw histograms, but can be
    used to draw very simple bar charts. It also appears to be the approach
    used by the \LPack{bar} package~\cite{bleser:94} for \LaTeX\ 2.09, which
    defines an environment for drawing bar charts. However, the built-in
    drawing tools are quite limited and work on the \LPack{bar} package appears
    to have ceased after 1994.

    More sophisticated drawing tools have been developed for use with \TeX\ and
    \LaTeX, notably \verb|eepic|, \verb|texdraw| and \verb|latexdraw|,
    \verb|LaTeXPiX|, MetaPost, \LPack{mfpic}, and \LPack{pstricks}. Any of these
    tools might be used to create bar charts; however, none of them has
    built-in support for doing so, and bar charts must be drawn using the
    ``brute force'' method --- manually drawing boxes to represent the bars in
    the chart. Depending on the tool, the axes of the chart might also need to
    be drawn manually. The \LPack{pst-bar} package is intended to automate the
    process of drawing bar charts using \LPack{pstricks}.

    There are currently two existing solutions for producing bar charts using
    \verb|pstricks|. One is the aforementioned brute force method in which a
    series of \Lcs{psframe}s are drawn with suitable heights, widths, and
    colors to produce the desired chart~\cite{voss:barcharts}. While this
    method works admirably and provides maximum flexibility, it is tedious and
    labor-intensive. The other option is the \LPack{bardiag} package, which
    essentially automates this approach~\cite{stepanyan:03}. While effective,
    \LPack{bardiag} requires a number of external packages to function, uses
    \LaTeX\ to perform its mathematical operations, and is not compatible with
    plain \TeX.

    These issues are all avoided by \LPack{pst-bar}. It calls only on packages
    that are part of the \verb|pstricks| family, provides extensive
    customization features, relies on Postscript for nearly all mathematical
    operations, and should be compatible with plain \TeX\ (untested).
    \verb|pst-bar| provides commands for reading data from a comma-delimited
    file to produce and label a bar chart. Multiple series of data may be
    plotted in either clustered or stacked form, and bars may be plotted either
    horizontally or vertically. An additional option allows block charts that
    display the differences between subsequent rows of data in the data file
    (see Section~\ref{sec:block}).

    At this stage, \verb|pst-bar| should be regarded as beta software.
    Revisions to the code between this release and the first stable release are
    not guaranteed to be backward compatible.

  \section{Drawing a Bar Chart}
    Drawing a bar chart with \verb|pst-bar| is a three-step process: (i) read
    the data file, (ii) draw the bars, and (iii) draw the axes. The first two
    step are accomplished directly with \verb|pst-bar|; the third requires the
    \LPack{pst-plot} package, a standard part of \verb|pstricks|.

    The following sections address the data file format, how to load data from
    the file, and how to use the data to produce a bar chart.

    \subsection{Data File Format}
      The data file must be comma-delimited with each row containing the same
      number of entries. A header row is permitted, but no header entry may
      contain commas or \Lcs{par} commands (including \verb|\\|). One of the
      data files used for the examples in this manual looks like
        \verbatiminput{example1.csv}%
      In this case, \verb|Set 1|, \verb|Set 2|, and \verb|Set 3| are the
      headers. The subsequent rows, hereafter referred to as \emph{data rows},
      contain the data associated with these headers. The file is arranged in a
      pseudo-columnar fashion, so that the data associated with \verb|Set 1|
      are \verb|1| and \verb|1|, those with \verb|Set 2| are \verb|2| and
      \verb|2|, and so on. After these data are plotted, the bars will be
      labeled with the text from the header row.

      \emph{Warning!} There are two very important conditions on the data
      within the file:
      \begin{itemize}
        \item All data outside of the header must be numeric. If there is no
          header row, all data in the file must be numeric.
        \item Each row must contain the same number of entries.
      \end{itemize}
      Failure to meet these conditions may result in Postscript errors or (less
      frequently) incorrectly labeled or drawn bar charts.

      How these data are plotted depends on the type of plot desired. See
      Sections~\ref{sec:cluster}--\ref{sec:block} and the examples in
      Section~\ref{sec:examples} for more on this.

    \subsection{Reading the Data File}
      Use the command \verb|\readpsbardata| to read from a data file:
      \begin{verbatim}
    \readpsbardata[<options>]{<data>}{<filename>}\end{verbatim}
      For the data, simply specify a macro name not currently in use.

      The available options are:
      \begin{center}
        \begin{tabular}{ll}
          \toprule
            Parameter     & Definition\\
          \midrule
            \Lkeyword{header} & \verb|true| if first line of data file is header
                            row\\
                          & \verb|false| otherwise\\
                          & Default: \verb|true|\\
          \bottomrule
        \end{tabular}
      \end{center}
      If \verb|header| is set to \verb|false|, \verb|pst-bar| will assume that
      no header is present and treat the first line of the file as data.

    \subsection{Drawing the Bars}
      \label{sec:drawing_bars}%
      The command \verb|\psbarchart| draws the bars for the bar chart.
      \begin{verbatim}
    \psbarchart[<options>]{<data>}\end{verbatim}
      For \verb|<data>|, use the macro name supplied to \Lcs{readpsbardata}.
      Bars are grouped in columns that are one \Lcs{psxunit} wide, and the
      number of bars appearing in a single column is equal to the number of
      data rows in the data file. It labels the bottom of each column with the
      headers from the data file if \Lkeyword{header} was set to to \verb|true|
      during \Lcs{readpsbardata}. It only creates the bars and the column
      labels --- axes and frames must be provided separately.

      The available options are:
      \begin{center}
        \begin{tabular}{ll}
          \toprule
            Parameter           & Definition\\
          \midrule
            \Lkeyword{chartstyle}   & \Lkeyval{cluster} produces a cluster of bars\\
                                & \Lkeyval{stack} stacks the cluster into a single
                                  column\\
                                & \Lkeyval{block} prints a ``floating'' bar with a
                                  nonzero minimum\\
                                & Default: \Lkeyval{cluster}\\
            \Lkeyword{barstyle}     & Name(s) of bar style(s) to use for each bar\\
                                & Default: \verb|{black,darkgray,gray,lightgray,white,red,green,blue}|\\
            \Lkeyword{barcolsep}    & Factor determining whitespace between
                                  columns\\
                                & Default: \verb|0.4|\\
            \Lkeyword{barsep}       & Factor determining whitespace between bars\\
                                & (\Lkeyval{cluster} and \Lkeyval{block} charts)\\
                                & Default: \verb|0.0|\\
            \Lkeyword{barlabelrot}  & Angle of rotation of the column labels\\
                                & Default: \verb|0|\\
            \Lkeyword{orientation}  & \Lkeyval{vertical} for vertically drawn bars\\
                                & \Lkeyval{horizontal} for horizontally drawn
                                  bars\\
                                & Default: \Lkeyval{vertical}\\
          \bottomrule%
        \end{tabular}
      \end{center}

      The number of \verb|barstyle|s specified must equal or exceed the number
      of bar segments in each column; otherwise, a Postscript error will
      result. For the \Lkeyval{cluster} and \Lkeyval{stack} \verb|chartstyle|s, this
      is equal to the number of data rows in the data file; for the
      \Lkeyval{block} \verb|chartstyle|, it is equal to half the number of data
      rows. Furthermore, when specifying the list of \verb|barstyle|s, the
      styles must be listed between curly braces, e.g.,
\begin{BDef}
\Lcs{psbarchart}\OptArgs\Largb{\ldots}
\end{BDef}

      The \Lkeyword{barstyle}s available by default are \Lkeyval{red}, \Lkeyval{green},
      \Lkeyval{blue}, \Lkeyval{black}, \Lkeyval{white}, \Lkeyval{gray}, \Lkeyval{lightgray},
      and \Lkeyval{darkgray}. Each of these plots a bar of the named color with
      square corners and a black outline. New \Lkeyword{barstyle}s may be defined
      using the \Lcs{newpsbarstyle} command described in
      Section~\ref{sec:customizing}.

      Figure~\ref{fig:bar_layout} shows how the \Lcs{psbarchart} lays out the
      bars for the default \Lkeyword{chartstyle}, \Lkeyval{cluster}. For the
      \Lkeyval{stack} \Lkeyword{chartstyle}, the \Lkeyword{barsep} option is ignored.

      \begin{figure}[t]
        \centering%
        \begin{pspicture}(0,0)(4in,2in)%
          \psframe[linestyle=dashed](0,0)(4in,2in)%
          \psframe[linestyle=none,fillstyle=hlines,hatchangle=45,%
            hatchcolor=lightgray,hatchwidth=0.4pt,hatchsep=8pt](0,0)(1in,2in)%
          \psframe[fillcolor=darkgray,fillstyle=solid](0.2in,0in)(0.45in,0.8in)%
          \psframe[fillcolor=lightgray,fillstyle=solid](0.55in,0in)(0.8in,1.1in)%
          \psline[linestyle=dotted](1in,0in)(1in,2in)%
          \psframe[fillcolor=darkgray,fillstyle=solid](1.2in,0in)(1.45in,0.6in)%
          \psframe[fillcolor=lightgray,fillstyle=solid](1.55in,0in)(1.8in,0.4in)%
          \psline[linestyle=dotted](2in,0in)(2in,2in)%
          \psframe[fillcolor=darkgray,fillstyle=solid](2.2in,0in)(2.45in,0.4in)%
          \psframe[fillcolor=lightgray,fillstyle=solid](2.55in,0in)(2.8in,0.3in)%
          \psline[linestyle=dotted](3in,0in)(3in,2in)%
          \psframe[fillcolor=darkgray,fillstyle=solid](3.2in,0in)(3.45in,1.1in)%
          \psframe[fillcolor=lightgray,fillstyle=solid](3.55in,0in)(3.8in,0.9in)%
          \rput[b](0.5in,1.8in){\small$\mathtt{\backslash psxunit}$}%
          \psline{->}(0.2in,1.87in)(0in,1.87in)%
          \psline{->}(0.8in,1.87in)(1in,1.87in)%
          \psline(0.45in,0.85in)(0.45in,1.3in)%
          \psline(0.55in,1.15in)(0.55in,1.3in)%
          \rput[l](0.8in,1.25in){\small$\mathtt{barsep} \times
            \mathtt{\backslash psxunit}$}%
          \psline{->}(0.75in,1.25in)(0.55in,1.25in)%
          \psline{->}(0.25in,1.25in)(0.45in,1.25in)%
          \psline{->}(0.6in,0.9in)(0.8in,0.9in)%
          \psline{->}(1.2in,0.9in)(1in,0.9in)%
          \rput[l](1.25in,0.9in){\small$0.5 \times \mathtt{barcolsep} \times
            \mathtt{\backslash psxunit}$}%
        \end{pspicture}
        \caption{\label{fig:bar_layout}%
          Schematic diagram for the layout of the bar chart. The hatched area
          marks the region in which data from the first column of the data file
          will be plotted. Bar width is equal to $[(1 - \mathtt{barsep} - 0.5
          \times \mathtt{barcolsep}) \times \mathtt{\backslash psxunit}] / N$,
          where $N$ is the number of bars in the column.
        }%
      \end{figure}

\subsection{Customizing the Chart}\label{sec:customizing}%
      To add a custom bar style, use the command \Lcs{newpsbarstyle},
\begin{BDef}
\Lcs{newpsbarstyle}\Largb{<name>}\Largb{<definition>}
\end{BDef}
      The name is a text string not currently used by any other
      \Lkeyword{barstyle}, and the definition may consist of any \LPack{pstricks}
      key or group of keys applicable to \Lcs{psframe}. For example, the
      \Lkeyval{red} \Lkeyword{barstyle} is defined as
\begin{BDef}
\Lcs{newpsbarstyle}\Largb{red}\Largb{\Lkeyset{fillcolor=red},\Lkeyset{fillstyle=solid},\Lkeyword{framearc}=0}
\end{BDef}

      To customize the type used to set the column labels, redefine
      \Lcs{psbarlabel}. For example, to have the label set in small italics,
      use
\begin{BDef}
\LcsStar{renewcommand}\Lcs{psbarlabel}\Largb{\small\itshape}
\end{BDef}
      By default, \Lcs{psbarlabel} sets the column label in the current text
      font.

      To adjust the spacing between the bars and the column labels, redefine
      \Lcs{psbarlabelsep}. Note that it is defined as a command, not a
      length, and should be redefined using \Lcs{renewcommand*}. By default
      it is \verb|0pt|.

      Finally, the data from the file may be scaled and manipulated using the
      command \Lcs{psbarscale},
\begin{BDef}
\Lcs{psbarscale}\Largr{<scale>}\Largb{<Postscript code>}
\end{BDef}
      inspired by Herbert Vo\ss' \verb|\pstScale| from
      \LPack{pstricks-add}~\cite{voss:04}. The data are scaled by the value in
      parentheses and may be further manipulated with Postscript code. For
      example, to plot the logarithm of the input data one would use
      \Lcs{psbarscale}\Largr{1}\Largb{log}. The Postscript code is applied to the data
      prior to scaling.

  \section{The Chart Styles}
    As described in Section~\ref{sec:drawing_bars}, there are three different
    \Lkeyword{chartstyle} options. The default, \Lkeyval{cluster} is the common bar
    chart with bars clustered into groups of related data. The second option,
    \Lkeyval{stack}, draws a series of bars stacked atop one another instead of
    sitting side-by-side in a cluster. The third, \Lkeyval{block}, draws clustered
    bars between two data points, thus displaying a range of values instead of
    a single value.

    The following sections describe each \Lkeyword{chartstyle} in detail, including
    how it uses the input data. Examples of use are provided in each case. Full
    examples, including axes, appear in Section~\ref{sec:examples}.

    \subsection{\texttt{cluster}}
      \label{sec:cluster}%
      For a \Lkeyval{cluster} chart, each comma-delimited variable within a given
      row represents a bar in a different column. Each row represents a new set
      of bars. Thus the file
      \verbatiminput{example1.csv}%
      produces the bars

      \hfill%
      \begin{minipage}[b]{1.5in}%
        \psset{unit=0.5in}%
        \begin{pspicture}(0,-0.5)(3,3)%
          \readpsbardata{\data}{example1.csv}%
          \psbarchart[barstyle={red,blue}]{\data}%
        \end{pspicture}
      \end{minipage}%
      \hfill%
      \begin{minipage}[b][1.75in][c]{3.5in}%
        \begin{verbatim}
\psset{unit=0.5in}%
\begin{pspicture}(0,-0.5)(3,3)%
  \readpsbardata{\data}{example1.csv}%
  \psbarchart[barstyle={red,blue}]{\data}%
\end{pspicture}\end{verbatim}
      \end{minipage}%
      \hfill%

    \subsection{\texttt{stack}}
      For a \Lkeyval{stack} chart, each column of the chart has only one bar. This
      bar consists of as many segments as the data file has data rows, with the
      data from each row stacked onto the previous row. Thus, the file
      \verbatiminput{example2.csv}%
      produces the bars

      \hfill%
      \begin{minipage}[b]{1.5in}%
        \psset{unit=0.5in}%
        \begin{pspicture}(0,-0.5)(3,4)%
          \readpsbardata{\data}{example2.csv}%
          \psbarchart[barstyle={red,blue},chartstyle=stack]{\data}%
        \end{pspicture}
      \end{minipage}
      \hfill%
      \begin{minipage}[b][2.25in][c]{3.5in}%
        \begin{verbatim}
\psset{unit=0.5in}%
\begin{pspicture}(0,-0.5)(3,4)%
  \readpsbardata{\data}{example2.csv}%
  \psbarchart[barstyle={red,blue},%
    chartstyle=stack]{\data}%
\end{pspicture}\end{verbatim}
      \end{minipage}
      \hfill%

      Notice that these bars are wider than those produced by
      \Lkeyset{chartstyle=cluster} because the bars are stacked vertically
      instead of being clustered along the bottom axis. A bar width similar to
      that of the \Lkeyval{cluster} chart in the previous section could be
      obtained by setting \Lkeyword{xunit}\verb|=0.25in|.

    \subsection{\texttt{block}}
      \label{sec:block}%
      For a \verb|block| chart, each bar represents a range of values. As such,
      each bar requires two data lines from the data file, one denoting the
      upper limit and the other the lower limit. If there are multiple pairs of
      data lines, they are plotted in a clustered fashion. If there are an odd
      number of data lines, the last line of the data file is ignored. Thus,
      the file
      \verbatiminput{example3.csv}%
      produces the bars

      \hfill%
      \begin{minipage}[b]{1.5in}%
        \psset{unit=0.5in}%
        \begin{pspicture}(0,-0.5)(3,3.5)%
          \readpsbardata{\data}{example3.csv}%
          \psbarchart[barstyle={red,blue},chartstyle=block]{\data}%
        \end{pspicture}
      \end{minipage}%
      \hfill%
      \begin{minipage}[b][1.5in][c]{3.5in}%
        \begin{verbatim}
\psset{unit=0.5in}%
\begin{pspicture}(0,-0.5)(3,3.5)%
  \readpsbardata{\data}{example3.csv}%
  \psbarchart[barstyle={red,blue},%
    chartstyle=block]{\data}%
\end{pspicture}\end{verbatim}
      \end{minipage}

  \section{Examples}
    \label{sec:examples}%
    Basic examples of each type including axes and gridlines:

    \begin{verbatim}
\begin{filecontents*}{example2.csv}
  Set 1, Set 2, Set 3
  1, 2, 3
  0.5, 1.5, 1
\end{filecontents*}\end{verbatim}

    \hfill%
    \begin{minipage}[b]{1.5in}%
      \psset{unit=0.5in}%
      \begin{pspicture}(0,-0.5)(3,4.5)%
        \psgrid[xunit=1.5in,gridlabels=0,subgriddiv=0,griddots=30](0,0)(1,4)%
        \psaxes[axesstyle=frame,Ox=0,Dx=1,labels=y,ticks=y](0,0)(3,4)%
        \readpsbardata{\data}{example2.csv}%
        \psbarchart[barstyle={red,blue}]{\data}%
      \end{pspicture}
    \end{minipage}%
    \hfill%
    \begin{minipage}[b][2.25in][c]{3.5in}%
      \begin{verbatim}
\psset{unit=0.5in}%
\begin{pspicture}(0,-0.5)(3,4.5)%
  \psgrid[xunit=1.5in,gridlabels=0,%
    subgriddiv=0,griddots=30](0,0)(1,4)%
  \psaxes[axesstyle=frame,Ox=0,Dx=1,labels=y,%
    ticks=y](0,0)(3,4)%
  \readpsbardata{\data}{example2.csv}%
  \psbarchart[barstyle={red,blue}]{\data}%
\end{pspicture}\end{verbatim}
    \end{minipage}

    \hfill%
    \begin{minipage}[b]{1.5in}%
      \psset{unit=0.5in}%
      \begin{pspicture}(0,-0.5)(3,4.5)%
        \psgrid[xunit=1.5in,gridlabels=0,subgriddiv=0,griddots=30](0,0)(1,4)%
        \psaxes[axesstyle=frame,Ox=0,Dx=1,labels=y,ticks=y](0,0)(3,4)%
        \readpsbardata{\data}{example2.csv}%
        \psbarchart[barstyle={red,blue},chartstyle=stack]{\data}%
      \end{pspicture}
    \end{minipage}%
    \hfill%
    \begin{minipage}[b][2.25in][c]{3.5in}%
      \begin{verbatim}
\psset{unit=0.5in}%
\begin{pspicture}(0,-0.5)(3,4.5)%
  \psgrid[xunit=1.5in,gridlabels=0,%
    subgriddiv=0,griddots=30](0,0)(1,4)%
  \psaxes[axesstyle=frame,Ox=0,Dx=1,labels=y,%
    ticks=y](0,0)(3,4)%
  \readpsbardata{\data}{example2.csv}%
  \psbarchart[barstyle={red,blue},%
    chartstyle=stack]{\data}%
\end{pspicture}\end{verbatim}
    \end{minipage}

    \hfill%
    \begin{minipage}[b]{1.5in}%
      \psset{unit=0.5in}%
      \begin{pspicture}(0,-0.5)(3,4.5)%
        \psgrid[xunit=1.5in,gridlabels=0,subgriddiv=0,griddots=30](0,0)(1,4)%
        \psaxes[axesstyle=frame,Ox=0,Dx=1,labels=y,ticks=y](0,0)(3,4)%
        \readpsbardata{\data}{example2.csv}%
        \psbarchart[barstyle={red,blue},chartstyle=block]{\data}%
      \end{pspicture}
    \end{minipage}%
    \hfill%
    \begin{minipage}[b][2.25in][c]{3.5in}%
      \begin{verbatim}
\psset{unit=0.5in}%
\begin{pspicture}(0,-0.5)(3,4.5)%
  \psgrid[xunit=1.5in,gridlabels=0,%
    subgriddiv=0,griddots=30](0,0)(1,4)%
  \psaxes[axesstyle=frame,Ox=0,Dx=1,labels=y,%
    ticks=y](0,0)(3,4)%
  \readpsbardata{\data}{example2.csv}%
  \psbarchart[barstyle={red,blue},%
    chartstyle=block]{\data}%
\end{pspicture}\end{verbatim}
    \end{minipage}

    Using \verb|\newpsbarstyle|:

    \hfill%
    \begin{minipage}[b]{1.5in}%
      \psset{unit=0.5in}%
      \newpsbarstyle{yellowhatch}{framearc=0.5,fillstyle=hlines*,rot=45,fillcolor=yellow}%
      \newpsbarstyle{redoutline}{framearc=0.5,fillcolor=black,linecolor=red,linewidth=1.5pt}%
      \begin{pspicture}(0,-0.5)(3,4.5)%
        \psgrid[xunit=1.5in,gridlabels=0,subgriddiv=0,griddots=30](0,0)(1,4)%
        \psaxes[axesstyle=frame,Ox=0,Dx=1,labels=y,ticks=y](0,0)(3,4)%
        \readpsbardata{\data}{example2.csv}%
        \psbarchart[barstyle={yellowhatch,redoutline}]{\data}%
      \end{pspicture}
    \end{minipage}%
    \hfill%
    \begin{minipage}[b][2.75in][c]{3.5in}%
      \begin{verbatim}
\psset{unit=0.5in}%
\newpsbarstyle{yellowhatch}{framearc=0.5,%
  fillstyle=hlines*,rot=45,fillcolor=yellow}%
\newpsbarstyle{redoutline}{framearc=0.5,%
  fillcolor=black,linecolor=red,%
  linewidth=1.5pt}%
\begin{pspicture}(0,-0.5)(3,4.5)%
  \psgrid[xunit=1.5in,gridlabels=0,%
    subgriddiv=0,griddots=30](0,0)(1,4)%
  \psaxes[axesstyle=frame,Ox=0,Dx=1,labels=y,%
    ticks=y](0,0)(3,4)%
  \readpsbardata{\data}{example2.csv}%
  \psbarchart[barstyle={yellowhatch,%
    redoutline}]{\data}%
\end{pspicture}\end{verbatim}
    \end{minipage}

    Using \verb|[orientation=horizontal]|:

    \hfill%
    \begin{minipage}[b]{2in}%
      \psset{unit=0.5in}%
      \newpsbarstyle{yellowhatch}{framearc=0.5,fillstyle=hlines*,rot=45,fillcolor=yellow}%
      \newpsbarstyle{redoutline}{framearc=0.5,fillcolor=black,linecolor=red,linewidth=1.5pt}%
      \begin{pspicture}(0,-0.5)(4,3.5)%
        \psgrid[yunit=1.5in,gridlabels=0,subgriddiv=0,griddots=30](0,0)(3,1)%
        \psaxes[axesstyle=frame,Ox=0,Dx=1,labels=x,ticks=x](0,0)(3,3)%
        \readpsbardata{\data}{example2.csv}%
        \psbarchart[barstyle={yellowhatch,redoutline},orientation=horizontal]{\data}%
      \end{pspicture}
    \end{minipage}%
    \hfill%
    \begin{minipage}[b][2.75in][c]{3.5in}%
      \begin{verbatim}
\psset{unit=0.5in}%
\newpsbarstyle{yellowhatch}{framearc=0.5,%
  fillstyle=hlines*,rot=45,fillcolor=yellow}%
\newpsbarstyle{redoutline}{framearc=0.5,%
  fillcolor=black,linecolor=red,%
  linewidth=1.5pt}%
\begin{pspicture}(0,-0.5)(3,4.5)%
  \psgrid[xunit=1.5in,gridlabels=0,%
    subgriddiv=0,griddots=30](0,0)(1,4)%
  \psaxes[axesstyle=frame,Ox=0,Dx=1,labels=y,%
    ticks=y](0,0)(3,4)%
  \readpsbardata{\data}{example2.csv}%
  \psbarchart[barstyle={yellowhatch,%
    redoutline}]{\data}%
\end{pspicture}\end{verbatim}
    \end{minipage}

    Sophisticated effects are possible using multiple calls to
    \Lcs{psbarchart} in a single chart. For example, a particular important
    bar may be highlighted in green by splitting the data into two files, one
    containing a zero for the data value to be highlighted, and the other
    containing zeros for all of the data \emph{except} the value to be
    highlighted.

    \vspace*{2ex}%

    File 1 (\verb|example4.csv|):
    \verbatiminput{example4.csv}%

    File 2 (\verb|example5.csv|):
    \verbatiminput{example5.csv}%
    Notice that the second file has no header row in order to prevent the bar
    labels from being printed twice.

    \hfill%
    \begin{minipage}[b]{1.5in}%
      \psset{unit=0.5in}%
      \begin{pspicture}(0,-0.5)(3,4.5)%
        \psgrid[xunit=1.5in,gridlabels=0,subgriddiv=0,griddots=30](0,0)(1,4)%
        \psaxes[axesstyle=frame,Ox=0,Dx=1,labels=y,ticks=y](0,0)(3,4)%
        \readpsbardata{\data}{example4.csv}%
        \psbarchart[barstyle={blue}]{\data}%
        \readpsbardata[header=false]{\data}{example5.csv}%
        \psbarchart[barstyle={green}]{\data}%
      \end{pspicture}
    \end{minipage}%
    \hfill%
    \begin{minipage}[b][2.25in][c]{3.5in}%
      \begin{verbatim}
\psset{unit=0.5in}%
\begin{pspicture}(0,-0.5)(3,4.5)%
  \psgrid[xunit=1.5in,gridlabels=0,%
    subgriddiv=0,griddots=30](0,0)(1,4)%
  \psaxes[axesstyle=frame,Ox=0,Dx=1,labels=y,%
    ticks=y](0,0)(3,4)%
  \readpsbardata{\data}{example4.csv}%
  \psbarchart[barstyle={blue}]{\data}%
  \readpsbardata[header=false]{\data}%
    {example5.csv}%
  \psbarchart[barstyle={green}]{\data}%
\end{pspicture}\end{verbatim}
    \end{minipage}

    Different chart styles may also be combined in a single bar chart.

    \vspace*{2ex}%

    File 1 (\verb|example6.csv|): \verbatiminput{example6.csv}%

    File 2 (\verb|example7.csv|): \verbatiminput{example7.csv}%

    \hfill%
    \begin{minipage}[b]{1.5in}%
      \psset{unit=0.5in}%
      \begin{pspicture}(0,-0.5)(3,4.5)%
        \psgrid[xunit=1.5in,gridlabels=0,subgriddiv=0,griddots=30](0,0)(1,4)%
        \psaxes[axesstyle=frame,Ox=0,Dx=1,labels=y,ticks=y](0,0)(3,4)%
        \readpsbardata{\data}{example6.csv}%
        \psbarchart[barstyle={black}]{\data}%
        \readpsbardata[header=false]{\data}{example7.csv}%
        \psbarchart[barstyle={red},chartstyle=block,barcolsep=0.8]{\data}%
      \end{pspicture}
    \end{minipage}%
    \hfill%
    \begin{minipage}[b][2.25in][c]{3.5in}%
      \begin{verbatim}
\psset{unit=0.5in}%
\begin{pspicture}(0,-0.5)(3,4.5)%
  \psgrid[xunit=1.5in,gridlabels=0,%
    subgriddiv=0,griddots=30](0,0)(1,4)%
  \psaxes[axesstyle=frame,Ox=0,Dx=1,labels=y,%
    ticks=y](0,0)(3,4)%
  \readpsbardata{\data}{example6.csv}%
  \psbarchart[barstyle={black}]{\data}%
  \readpsbardata[header=false]{\data}%
    {example7.csv}%
  \psbarchart[barstyle={red},chartstyle=block,%
    barcolsep=0.8]{\data}%
\end{pspicture}
\end{pspicture}\end{verbatim}
    \end{minipage}

  \section{To Do}
    \begin{itemize}
      \item Provide commands to facilitate legend creation and placement.
      \item Allow the automatic labeling of bars with values from the data
        file.
      \item Allow the automatic labeling of bars with labels of the user's
        choice.
      \item Improve header parsing to allow commas within header entries.
      \item Add error-checking to ensure that each row of the data file
        contains the same number of entries, throwing an error in \TeX\ or
        \LaTeX\ if not.
      \item Improve documentation.
    \end{itemize}

\nocite*
\bibliographystyle{plain}%
\bibliography{pst-bar-doc}%

\printindex


\end{document}