skyvector
Plots directed lines from the data position given delta values for the coordinates. The plotted markers are typically little arrows, but there are other options.
In some cases such delta values may be the actual magnitude required for the plot, but often the vector data represents a value which has a different magnitude or is in different units to the positional data. As a convenience for this case, the plotter can optionally scale the magnitudes of all the vectors to make them a sensible size, so by default the largest ones are a few tens of pixels long. This auto-scaling is in operation by default, but it can be turned off or adjusted with the scaling and auto-scaling options.
Usage Overview:
layerN=skyvector arrowN=small_arrow|medium_arrow|... scaleN=<factor> autoscaleN=true|false shadingN=auto|flat|translucent|transparent|density|aux|weighted <shade-paramsN> lonN=<deg-expr> latN=<deg-expr> dlonN=<deg-expr> dlatN=<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=tgas_source.fits lon=ra lat=dec layer1=mark layer2=skyvector dlon2=pmra dlat2=pmdec arrow2=medium_arrow clon=56.75 clat=24.10 radius=1.5
arrowN = small_arrow|medium_arrow|...
??????(ErrorRenderer)
The available options are:
small_arrow
medium_arrow
large_arrow
small_open_dart
medium_open_dart
large_open_dart
small_filled_dart
medium_filled_dart
large_filled_dart
lines
capped_lines
[Default: small_arrow
]
autoscaleN = true|false
??????(Boolean)
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
]
dlatN = <deg-expr>
??????(String)
The value is a numeric algebraic expression based on column names as described in Section 10.
dlonN = <deg-expr>
??????(String)
The value is a numeric algebraic expression based on column names as described in Section 10.
icmdN = <cmds>
??????(ProcessingStep[])
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)
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)
-
",
meaning standard input.
In this case the input format must be given explicitly
using the ifmtN
parameter.
Note that not all formats can be streamed in this way.<
" character at the start,
or a "|
" character at the end
("<syscmd
" or
"syscmd|
").
This executes the given pipeline and reads from its
standard output.
This will probably only work on unix-like systems.istreamN = true|false
??????(Boolean)
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)
The value is a numeric algebraic expression based on column names as described in Section 10.
lonN = <deg-expr>
??????(String)
The value is a numeric algebraic expression based on column names as described in Section 10.
scaleN = <factor>
??????(Double)
[Default: 1
]
shadingN = auto|flat|translucent|transparent|density|aux|weighted <shade-paramsN>
??????(ShapeMode)
[Default: auto
]