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

8.3.23 skyellipse

Plots an ellipse (or rectangle, triangle, or other similar figure) defined by two principal radii and an optional rotation angle.

Usage Overview:

   layerN=skyellipse ellipseN=ellipse|crosshair_ellipse|... scaleN=<factor>
                     autoscaleN=true|false
                     shadingN=auto|flat|translucent|transparent|density|aux|weighted <shade-paramsN>
                     lonN=<deg-expr> latN=<deg-expr> raN=<deg-expr>
                     rbN=<deg-expr> posangN=<deg-expr> inN=<table>
                     ifmtN=<in-format> istreamN=true|false icmdN=<cmds>

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

Example:

   stilts plot2sky in=mgc_ok.fits
                   lon=mgc_alpha_j2000 lat=mgc_delta_j2000
                   ra=bulge_re/3600. rb=bulge_re*bulge_e/3600. posang=bulge_pa
                   autoscale=false scale=10 color=#cc00ff
                   layer1=skyellipse ellipse1=filled_ellipse shading1=transparent opaque1=4
                   layer2=skyellipse ellipse2=crosshair_ellipse
                   clon=180.1 clat=0 radius=0.25

autoscaleN = true|false       (Boolean)
Determines whether the default size of variable-sized markers like vectors and ellipses are automatically scaled to have a sensible size. If true, then the sizes of all the plotted markers are examined, and some dynamically calculated factor is applied to them all to make them a sensible size (by default, the largest ones will be a few tens of pixels). If false, the sizes will be the actual input values interpreted in data coordinates.

If auto-scaling is on, then markers will keep approximately the same screen size during zoom operations; if it's off, they will keep the same size in data coordinates.

Marker size is also affected by the scale parameter.

[Default: true]

ellipseN = ellipse|crosshair_ellipse|...       (ErrorRenderer)
How ellipses are represented.

The available options are:

[Default: ellipse]

icmdN = <cmds>       (ProcessingStep[])
Specifies processing to be performed on the layer N input table as specified by parameter inN. The value of this parameter is one or more of the filter commands described in Section 6.1. If more than one is given, they must be separated by semicolon characters (";"). This parameter can be repeated multiple times on the same command line to build up a list of processing steps. The sequence of commands given in this way defines the processing pipeline which is performed on the table.

Commands may alteratively be supplied in an external file, by using the indirection character '@'. Thus a value of "@filename" causes the file filename to be read for a list of filter commands to execute. The commands in the file may be separated by newline characters and/or semicolons.

ifmtN = <in-format>       (String)
Specifies the format of the input table as specified by parameter inN. The known formats are listed in Section 5.2.1. This flag can be used if you know what format your table is in. If it has the special value (auto) (the default), then an attempt will be made to detect the format of the table automatically. This cannot always be done correctly however, in which case the program will exit with an error explaining which formats were attempted.

[Default: (auto)]

inN = <table>       (StarTable)
The location of the input table. This may take one of the following forms: In any case, compressed data in one of the supported compression formats (gzip, Unix compress or bzip2) will be decompressed transparently.
istreamN = true|false       (Boolean)
If set true, the input table specified by the inN parameter will be read as a stream. It is necessary to give the ifmtN parameter in this case. Depending on the required operations and processing mode, this may cause the read to fail (sometimes it is necessary to read the table more than once). It is not normally necessary to set this flag; in most cases the data will be streamed automatically if that is the best thing to do. However it can sometimes result in less resource usage when processing large files in certain formats (such as VOTable).

[Default: false]

latN = <deg-expr>       (String)
Latitude in decimal degrees.

The value is a numeric algebraic expression based on column names as described in Section 10.

lonN = <deg-expr>       (String)
Longitude in decimal degrees.

The value is a numeric algebraic expression based on column names as described in Section 10.

posangN = <deg-expr>       (String)
Orientation of the ellipse. The value is the angle in degrees from the North pole to the primary axis of the ellipse in the direction of increasing longitude.

The value is a numeric algebraic expression based on column names as described in Section 10.

raN = <deg-expr>       (String)
Ellipse first principal radius in degrees.

The value is a numeric algebraic expression based on column names as described in Section 10.

rbN = <deg-expr>       (String)
Ellipse second principal radius in degrees. If this value is blank, the two radii will be assumed equal, i.e. the ellipses will be circles.

The value is a numeric algebraic expression based on column names as described in Section 10.

scaleN = <factor>       (Double)
Affects the size of variable-sized markers like vectors and ellipses. The default value is 1, smaller or larger values multiply the visible sizes accordingly.

[Default: 1]

shadingN = auto|flat|translucent|transparent|density|aux|weighted <shade-paramsN>       (ShapeMode)
Determines how plotted objects in layer N are coloured. This may be influenced by how many objects are plotted over each other as well as the values of other parameters. Available options (Section 8.4) are: Each of these options comes with its own set of parameters to specify the details of how colouring is done.

[Default: auto]


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

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