## input data formats | Welcome Gallery Handbook |
| Manual page for input_data_formats(PL)

## DESCRIPTION

Plotting is driven by data. The plot data may be specified within a ploticus script, or it may be contained in a file, or be the result of executing a shell command.`` proc getdata is used to specify or read in plotting data.``

Ploticus uses field-oriented data. Most plotting is done based on fields. For example, a bargraph can be rendered based upon the values in field #2 of each row of data. A set of data should contain one or more rows (lines).``

Fields may be delimited in one of three ways. The delimitation must be specified in proc getdata.`` The three ways are:

- white-space (any combination of spaces or tabs)
- comma (often called spreadsheet or .csv)
- tab

Fields may be surrounded by "double quotes"; this must be done when a field contains embedded delimiter characters.``

The number of fields should be consistent across records.``

A comment character (specified as a proc getdata attribute) may be given as the first character on a line; it causes that line to be ignored.``

Beginning in version 1.40 it is possible to set ploticus variables from within a data file using the construct: `#set VARIABLE = value`.``

## EXAMPLES

Gallery examples include:
scat7.dat (white-space delimited)
stock.csv (comma delimited)
timeline3 (data specified within script)
km2 (data specified within script).``

## DETAILS

The plotting procedures generally access specific fields and process the data from top to bottom. For example, a bar graph might be made by drawing one bar for each data record based on the value in field 2.``

Proc getdata is used to read in a data file for plotting.`` After proc getdata has been executed, the plotting procedures can access the data by record and field.``

## HANDLING MISSING DATA

Ploticus can handle missing plot data values.`` In data sets that are to be plotted, missing items should be denoted by a value that is not plottable, e.g.`` for numeric data, a value that is non-numeric.`` The plotting procedures omit non-plottable values (the details of how this is handled are given in the man page for each plotting proc).`` An Gallery example involving missing numeric data represented by dashes(-) is volunteers
data display engine
Copyright Steve Grubb
data display engine
Copyright Steve Grubb

Markup created by unroff 1.0, `` `` August 30, 2001.