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8.3.35 function

Plots an analytic function. This layer is currently only available for the Plane plots (including histogram).

Usage Overview:

   layerN=function axisN=Horizontal|Vertical xnameN=<name> fexprN=<expr>
                   colorN=<rrggbb>|red|blue|... thickN=<pixels>
                   dashN=dot|dash|...|<a,b,...> antialiasN=true|false

All the parameters listed here affect only the relevant layer, identified by the suffix N.

Example:

   stilts plot2plane layer1=function fexpr1=sin(x)/x thick1=3
                     xmin=0 xmax=30 ymin=-0.25 ymax=0.25

antialiasN = true|false       (Boolean)
If true, plotted lines are drawn with antialising. Antialised lines look smoother, but may take perceptibly longer to draw. Only has any effect for bitmapped output formats.

[Default: false]

axisN = Horizontal|Vertical       (FuncAxis)
Which axis the independent variable varies along. Options are currently Horizontal and Vertical.

[Default: Horizontal]

colorN = <rrggbb>|red|blue|...       (Color)
The color of plotted data, given by name or as a hexadecimal RGB value.

The standard plotting colour names are red, blue, green, grey, magenta, cyan, orange, pink, yellow, black, light_grey, white. However, many other common colour names (too many to list here) are also understood. The list currently contains those colour names understood by most web browsers, from AliceBlue to YellowGreen, listed e.g. in the Extended color keywords section of the CSS3 standard.

Alternatively, a six-digit hexadecimal number RRGGBB may be supplied, optionally prefixed by "#" or "0x", giving red, green and blue intensities, e.g. "ff00ff", "#ff00ff" or "0xff00ff" for magenta.

[Default: red]

dashN = dot|dash|...|<a,b,...>       (float[])
Determines the dash pattern of the line drawn. If null (the default), the line is solid.

Possible values for dashed lines are dot, dash, longdash, dotdash. You can alternatively supply a comma-separated list of on/off length values such as "4,2,8,2".

fexprN = <expr>       (String)
An expression using TOPCAT's expression language in terms of the independent variable to define the function. This expression must be standalone - it cannot reference any tables.
thickN = <pixels>       (Integer)
Thickness of plotted line in pixels.

[Default: 1]

xnameN = <name>       (String)
Name of the independent variable for use in the function expression. This is typically x for a horizontal independent variable and y for a vertical independent variable, but any string that is a legal expression language identifier (starts with a letter, continues with letters, numbers, underscores) can be used.

[Default: x]


Next Previous Up Contents
Next: skyvector
Up: Layer Types
Previous: gaussian

STILTS - Starlink Tables Infrastructure Library Tool Set
Starlink User Note256
STILTS web page: http://www.starlink.ac.uk/stilts/
Author email: m.b.taylor@bristol.ac.uk
Mailing list: topcat-user@jiscmail.ac.uk