label
Draws a text label at each position. You can select the font, where the labels appear in relation to the point positions, and how crowded the points have to get before they are suppressed.
Usage Overview:
layerN=label texttypeN=plain|antialias|latex fontsizeN=<int-value> fontstyleN=standard|serif|mono fontweightN=plain|bold|italic|bold_italic anchorN=west|east|north|south|center colorN=<rrggbb>|red|blue|... xoffN=<pixels> yoffN=<pixels> spacingN=<pixels> crowdlimitN=<n> <pos-coord-paramsN> labelN=<txt-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
.
<pos-coord-paramsN>
give a position for each row of the input table.
Their form depends on the plot geometry,
i.e. which plotting command is used.
For a plane plot (plot2plane
)
the parameters would be
xN
and yN
.
The coordinate parameter values are in all cases strings
interpreted as numeric expressions based on column names.
These can be column names, fixed values or algebraic
expressions as described in Section 10.
Example:
stilts plot2sky in=messier.xml lon=RA lat=DEC layer1=mark size1=3 layer2=label label2=NAME color2=black
anchorN = west|east|north|south|center
(Anchor)
The available options are:
west
east
north
south
center
[Default: west
]
colorN = <rrggbb>|red|blue|...
(Color)
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
]
crowdlimitN = <n>
(Integer)
It is useful for instance if you are looking at pairs of points, which will always be close together; if you set this value to 2, an isolated pair of labels can be seen, but if it's 1 then they will only be plotted when they are distant from each other, which may only happen at very high magnifications.
[Default: 2
]
fontsizeN = <int-value>
(Integer)
[Default: 12
]
fontstyleN = standard|serif|mono
(FontType)
The available options are:
standard
serif
mono
[Default: standard
]
fontweightN = plain|bold|italic|bold_italic
(FontWeight)
The available options are:
plain
bold
italic
bold_italic
[Default: plain
]
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 alternatively 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,
and lines which are blank or which start with a
'#
' character are ignored.
A backslash character '\
' at the end of a line
joins it with the following line.
ifmtN = <in-format>
(String)
inN
.
The known formats are listed in Section 5.1.1.
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.
This parameter is ignored for scheme-specified tables.
[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.:<scheme-name>:<scheme-args>
.<
" 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).
This parameter is ignored for scheme-specified tables.
[Default: false
]
labelN = <txt-expr>
(String)
The value is a string algebraic expression based on column names as described in Section 10.
spacingN = <pixels>
(Integer)
[Default: 12
]
texttypeN = plain|antialias|latex
(TextSyntax)
Plain
and
Antialias
both take the text at face value,
but Antialias
smooths the characters.
LaTeX
interprets the text as LaTeX source code
and typesets it accordingly.
When not using LaTeX, antialiased text usually looks nicer, but can be perceptibly slower to plot. At time of writing, on MacOS antialiased text seems to be required to stop the writing coming out upside-down for non-horizontal text (MacOS java bug).
[Default: plain
]
xoffN = <pixels>
(Integer)
[Default: 0
]
yoffN = <pixels>
(Integer)
[Default: 0
]