Plotting Styles and Attributes

Many different aspects of the appearance of line graphics produced by KAPPA applications can be controlled by specifying a plotting style when running the application. This includes things like the colour, line width, line style, character size, and font, each of which can be specified individually for different components of a plot (e.g. the tick marks, numerical labels, border, textual labels, etc.).

Each aspect of a plot is controlled by a plotting attribute. A plotting attribute has a name and a value.

Strings which assign new values to particular plotting attributes are called attribute setting strings. For instance:

   Border=1
   Title=This is my plot title

are two attribute setting strings. The first assigns the value 1 to the attribute called Border, and the second assigns the string "This is my plot title" to the attribute with name Title (attribute names are case insensitive but cannot be abbreviated).

Here is a list of the available attributes, with a brief description of each. Full descriptions are included later.

Border: Draw a border around valid regions of a plot?
Colour(element): Colour for a plot element
DrawAxes: Draw axes?
DrawDSB: Annotate both sidebands in a dual sideband spectrum?
DrawTitle: Draw a title?
Edge(axis): Which edges to label
FileInTitle: Include the NDF name as a second line in the title?
Font(element): Character font for a plot element
Gap(axis): Interval between major axis values
Grid: Draw grid lines?
LabelAt(axis): Where to place numerical labels
LabelUnits(axis): Include unit descriptions in axis labels?
LabelUp(axis): Draw numerical axis labels upright?
Labelling: Label and tick placement option
MajTickLen: Length of major tick marks
MinTickLen: Length of minor tick marks
MinTick(axis): Density of minor tick marks
NumLab(axis): Draw numerical axis labels?
NumLabGap(axis): Spacing of numerical axis labels
Size(element): Character size for a plot element
Style(element): Line style for a plot element
TextBackColour: Background colour to use when drawing text
TextLab(axis): Draw descriptive axis labels?
TextLabGap(axis): Spacing of descriptive axis labels
TickAll: Draw tick marks on all edges?
TitleGap: Vertical spacing for the title
Tol: Plotting tolerance
Width(element): Line width for a plot element

Some attribute names can be qualified so that they refer to a particular component of the plot. This is done by putting the qualifier in parentheses after the attribute name. For instance:

   Colour(border)=2
   Edge(2)=left

assigns the value 2 to the Colour attribute for the plot border, and assigns the value left to the Edge attribute for the second axis. The full description of each attribute describes what happens if you omit the qualifier. Attribute names which end in "(axis)" in the above list can be qualified by an integer axis index to refer to a particular plot axis. Attribute names which end in "(element)" in the above list can be qualified by any of the following strings to refer to a particular component of the plot (the qualifiers are case-insensitive and unambiguous abbreviations may be used):

Axes: Axis lines drawn through tick marks within the plotting area, drawn if attribute DrawAxes is given a non-zero value. Values set using Axes are only only used if axis-specific values have not been set using Axis1 or Axis2. Thus, Axes provides default values for Axis1 and Axis2.
Axis1: An axis line drawn through tick marks on axis 1 within the plotting area, drawn if attribute DrawAxes is given a non-zero value. Values specified using Axis1 override any supplied using Axes.
Axis2: An axis line drawn through tick marks on axis 2 within the plotting area, drawn if attribute DrawAxes is given a non-zero value. Values specified using Axis2 override any supplied using Axes.
Border: The plot border, drawn if attribute Border is given a non-zero value.
Curves: Curves drawn over the top of a plot (e.g. contours, data curves).
Grid: The grid lines, drawn if attribute Grid is given a non-zero value. Values set using Grid are only only used if axis-specific values have not been set using Grid1 or Grid2. Thus, Grid provides default values for Grid1 and Grid2.
Grid1: Grid lines which cross axis 1, drawn if attribute Grid is given a non-zero value. Values specified using Grid1 override any supplied using Grid.
Grid2: Grid lines which cross axis 2, drawn if attribute Grid is given a non-zero value. Values specified using Grid2 override any supplied using Grid.
Markers: Graphical markers (symbols) drawn over a plot.
NumLab: Numerical axis labels drawn around annotated axes. Values set using NumLab are only only used if axis-specific values have not been set using NumLab1 or NumLab2. Thus, NumLab provides default values for NumLab1 and NumLab2.
NumLab1: Numerical labels drawn along axis 1. Values specified using NumLab1 override any supplied using NumLab.
NumLab2: Numerical labels drawn along axis 2. Values specified using NumLab2 override any supplied using NumLab.
Strings: Text strings drawn over a plot (except for axis labels and plot title).
TextLab: Descriptive axis labels drawn around annotated axes. Values set using TextLab are only only used if axis-specific values have not been set using TextLab1 or TextLab2. Thus, TextLab provides default values for TextLab1 and TextLab2.
TextLab1: Descriptive label for axis 1. Values specified using TextLab1 override any supplied using TextLab.
TextLab2: Descriptive label for axis 2. Values specified using TextLab2 override any supplied using TextLab.
Ticks: Tick marks (both major and minor) drawn along annotated axes. Values set using Ticks are only only used if axis-specific values have not been set using Ticks1 or Ticks2. Thus, Ticks provides default values for Ticks1 and Ticks2.
Ticks1: Tick marks (both major and minor) drawn along axis 1. Values specified using Ticks1 override any supplied using Ticks.
Ticks2: Tick marks (both major and minor) drawn along axis 2. Values specified using Ticks2 override any supplied using Ticks.
Title: The title drawn at the top of a plot.

A collection of attribute settings is called a plotting style. Attributes which are not specified in a plotting style take on default values as described later. An example of a plotting style is contained in the file $KAPPA_DIR/kappa_style.def. This file defines the default style used by KAPPA.

In general each graphical application will determine the plotting style to be used when drawing line graphics by accessing a parameter called STYLE. Some applications have more than one style parameter. For instance, applications such as CONTOUR and LINPLOT which produce keys to the content of the plot have a parameter called KEYSTYLE, in addition to the normal STYLE parameter. KEYSTYLE is used to specify the plotting style for the key, whereas STYLE is used to specify the plotting style for the main plot.