## Prefabs | Welcome Gallery Handbook |
| Manual page for Prefabs(PL)

## AVAILABLE PREFABS

chron - chronological data (dates, times, etc); tabulate by week, month, etc. | dist - frequency distribution histogram on a data field | lines - line plots with optional data points and error bars, up to 4 groups | pie - pie graphs
| stack - stacked bar graphs, up to 4 levels | scat - scatterplots | vbars - bar graph of 1 or 2 groups with error bars | vbars - with error bars only

## WHAT ARE PREFABS?

Prefabs are the easiest way to get started with ploticus.`` You can quickly generate common types of plots without coding any ploticus scripts.`` Just supply several key parameters on the command line or in the data file.`` Everything else uses defaults.``

The `-prefab` command line option tells pl to use a prefab.`` Any of the other command options may also be used along with `-prefab`.`` For example, to use the scat scatterplot prefab you might use a command such as this:

  `pl -prefab scat -png data=results.dat x=2 y=4 -scale 0.7`

Prefab scripts are ordinary ploticus scripts. A collection of prefab scripts are included with ploticus in the `./prefabs` directory.`` You can use this directory or set up one of your own.`` An environment variable called PLOTICUS_PREFABS must exist and contain the full path name of the directory where prefab scripts reside.``

PARAMETERS

Some parameters are standard (recognized by most of the prefabs); others are specific to the individual prefabs.

Parameters may be supplied on the pl command line as var=value pairs as seen in the above example.

Most parameters may also be embedded in an input data file, using the #set construct:

       #set x = 2
       #set y = 3
       #set title = Correlation of WBC vs. T-Chol

Some parameters cannot be set from within the data file because they control data scanning. These are data, delim, header, and comment.`` There may be others as noted for individual prefabs.``

OUTPUT FILE NAMES

The -o option may be used to specify output file name explicitly.`` If -o is not given, output file naming is similar to that of pl in other contexts.`` For the above example the output file would be named `scat.png` .``

CUSTOMIZATION

Prefabs allow quick looks at data, but there are often details that would be nice to control but can't be adjusted because there is no command line parameter to do so.`` One way to proceed is to copy a prefab script to your own directory and then modify your copy as needed.`` Another option is to make a new prefab variant in the prefabs directory.``

EXAMPLES

A number of examples are included for each prefab.`` The command that was used to produce each one is shown (the command line options `-gif -scale 0.7 -tightcrop` were also used but are omitted for brevity).`` All of the examples may be demonstrated by going to the prefabs directory (the command `echo $PLOTICUS_PREFABS` will show the name of that directory), and entering the given command.``

HINTS

The following pl command line options may be very useful with prefabs: `-scale`, `-color`, `-backcolor`, `-tightcrop`, and perhaps `-font`.``

Be careful not to confuse prefab parameters with pl command line options . Prefab parameters are given this way: `paramname=value`.`` Command line options are given this way: `-option` or `-option value`.``

Most shells allow a backslash (\) for breaking up long commands into two or more lines.``

You can get a multi line title by splitting it over two lines, eg:

        pl -prefab pie1 data=data1 fld=3 label=1 title="Travel expenditures
        By department
        Fiscal year 2000"

## STANDARD PARAMETERS FOR PREFABS

The following parameters are accepted by all prefabs unless otherwise stated.`` The data parameter is always required.

data

  Name of data file. Always required. May be given as `-` if data are to be read from standard input.``

x

  Data field to plot in X. Either a number (eg 2 for the 2nd field) or a name if a data file contains a header.``

y

  Data field to plot in Y.`` Either a number (eg 2 for the 2nd field) or a name if a data file contains a header.``

err

  Data field for plotting vertical error bar around ( x, y ).`` If not specified no error bars will be drawn.`` Either a number (eg 2 for the 2nd field) or a name if a data file contains a header.``

title

  A plot title to be centered at the top. The parameter titledet is also available for controlling details of title placement and appearance.``

xlbl

  Label for X axis. The parameter xlbldet is also available for controlling details of X label placement and appearance.`` For example, to adjust the label downward 8/10 inch: `-xlbldet=adjust=0,-0.8`.``

xrange

  Range for numeric X axis. This is two values, a min and a max. Example: `"xrange=0 100"` .`` xrange causes automatic scaling in X to be disabled.``

xinc

  Increment amount for numeric X axis.``

xlog

  Logarithmic X axis. Allowable values are `log` and `log+1`.``

xgrid

  If `yes`, vertical grid lines will be drawn at each X stub. May also be specified as a linedetails attribute.``

ylbl

  Label for Y axis. The parameter ylbldet is also available for controlling details of Y label placement and appearance.`` For example, to adjust the label leftward 8/10 inch: `-ylbldet=adjust=0,-0.8`.``

yrange

  Range for numeric Y axis. This is two values, a min and a max. Example: `"yrange=0 100"` For prefabs where it is appropriate, yrange may also be given as `yrange=0` which fixes the min at 0 but allows the max to be automatically determined from the data.`` When two values are given, yrange causes all automatic scaling in Y to be disabled.``

yinc

  Increment amount for numeric Y axis.``

ylog

  Logarithmic Y axis. Allowable values are `log` and `log+1`.``

ygrid

  If `yes`, horizontal grid lines will be drawn at each Y stub. May also be specified as a linedetails attribute.``

autow

  If `yes`, width of plotting area will be automatically determined by the data.``

stubvert

  If `yes`, X axis stubs will be rendered vertically.``

delim

  Data file field delimitation method, either `space`, `comma`, or `tab`. `space` is the default, and indicates that fields will be delimited on "white space". See data formats for more information.``

header

  `yes` if first non-comment line of data file contains field names.`` These names may be used to reference the data fields. Default is `no`.``

comment

  Indicates data file comment character or symbol.`` Default is `//`.``

select

  A conditional expression for selecting data records to include.`` One at-sign should be used, not two.`` Example: `select="@1 = A"`

include1

  Specifies a file containing ploticus script code. The code is included after the plotting area has been set up but before the data display is drawn. May be useful in adding baselines, etc.``

include2

  Specifies a file containing ploticus script code. The code is included after the data display is drawn. May be useful for adding annotation.``

## USER-CONTRIBUTED PREFABS

User-contributed prefabs are welcome and may be sent to `steve@sgpr.net`; please include the prefab script file and a man page giving at least one working example.``
data display engine
Copyright Steve Grubb

Markup created by unroff 1.0, `` `` September 14, 2001.