This chapter covers the production of Charts. The GINOGRAF definition of a chart is a two or two-and-a-half dimensional (block-filled) representation of data using rectangular columns, bars, steps or areas on a set of axes. This definition covers five main types of chart: Multi-column and Single column Histograms and Bar Charts (discrete values against continuous data); and Step Charts and Area Charts (continuous data and values).
Data for the five chart types is represented by lengths, heights or areas as shown below :
Column Width
First data position
Second data position
Data represented by
Histograms
Constant
Zero
Variable
Height
Bar Charts
Constant
Variable
Variable
Length
Step Charts
Variable
Fixed
Variable
Height and width
Area Charts
Variable
Variable
Variable
Length and width
Multi-data Set Histograms
Constant
Zero
Variable
Height
The chart drawing routines are split into two main groups: complete drawing routines which produce a fully annotated chart with a single routine call; and separate component routines which build up a chart in a modular fashion. The routine names are shown in the tables below:
While axis and graph titles can be added after the complete drawing routines have been called, the full flexibility of layout and style can only be achieved using the component routines as the complete drawing routine is provided to present user data as quickly as possible with the minimum of effort.
