Provided by: stilts_3.1.5-1_all bug


       stilts-plot2sky - Draws a sky plot


       stilts plot2sky [xpix=<int-value>] [ypix=<int-value>]
                       [insets=<top>,<left>,<bottom>,<right>] [omode=swing|out|cgi|discard|auto]
                       [storage=simple|cache|basic-cache] [seq=<suffix>[,...]]
                       [legend=true|false] [legborder=true|false] [legopaque=true|false]
                       [legseq=<suffix>[,...]] [legpos=<xfrac,yfrac>] [title=<value>]
                       [auxmap=<map-name>|<color>-<color>[-<color>...]] [auxclip=<lo>,<hi>]
                       [auxflip=true|false] [auxquant=<number>] [auxfunc=log|linear|sqrt|square]
                       [auxmin=<number>] [auxmax=<number>] [auxlabel=<text>] [auxcrowd=<factor>]
                       [auxwidth=<pixels>] [auxvisible=true|false] [forcebitmap=true|false]
                       [compositor=0..1] [animate=<table>] [afmt=<in-format>]
                       [astream=true|false] [acmd=<cmds>] [parallel=<int-value>]
                       [reflectlon=true|false] [grid=true|false]
                       [labelpos=Auto|External|Internal|Basic|Hybrid|None] [sex=true|false]
                       [crowd=<number>] [gridcolor=<rrggbb>|red|blue|...]
                       [labelcolor=<rrggbb>|red|blue|...] [gridaa=true|false]
                       [texttype=plain|antialias|latex] [fontsize=<int-value>]
                       [fontstyle=standard|serif|mono] [fontweight=plain|bold|italic|bold_italic]
                       [clon=<degrees>] [clat=<degrees>] [radius=<degrees>] [zoomfactor=<number>]
                       [leglabelN=<text>] [layerN=<layer-type> <layerN-specific-params>]


       plot2sky draws plots on the celestial sphere. This can be represented in a number of ways,
       controlled by the projection parameter; by default the view is of a rotatable sphere  seen
       from  the  outside  (which  approximates  to a tangent projection for small regions of the
       sky), but Aitoff and Plate Carée projections are also available. A number of  options  are
       also provided for drawing and labelling the grid showing celestial coordinates.

       Positional  coordinates  are  specified as lon, lat pairs giving longitude and latitude in
       decimal degrees. By default these are represented in the output in the  same,  unlabelled,
       coordinate system. However the command can can also transform between different coordinate
       systems if  you  specify  the  data  and  view  systems  e.g.:  plot2sky  viewsys=galactic
       layer1=mark in1=cat.fits lon1=RA2000 lat1=DEC2000 datasys1=equatorial

       Content  is  added  to  the  plot  by  specifying one or more plot layers using the layerN
       parameter. The N part is a suffix applied to all the parameters affecting a  given  layer;
       any  suffix  (including the empty string) may be used. Available layers for this plot type
       are: mark, size, sizexy, skyvector, skyellipse, skycorr,  link2,  mark2,  label,  contour,
       skydensity, healpix, skygrid.


              Size  of the output image in the X direction in pixels. This includes space for any
              axis labels, padding and other decoration outside the plot area  itself.  See  also

              Size  of the output image in the Y direction in pixels. This includes space for any
              axis labels, padding and other decoration outside the plot area  itself.  See  also

              Defines  the  amount of space in pixels around the actual plotting area. This space
              is used for axis labels, and other decorations and any left  over  forms  an  empty

              The  size  and position of the actual plotting area is determined by this parameter
              along with xpix and ypix.

              The   value   of    this    parameter    is    4    comma    separated    integers:
              <top>,<left>,<bottom>,<right>.  Any  or  all  of these values may be left blank, in
              which case the corresponding margin will be calculated automatically  according  to
              how much space is required.

              Determines how the drawn plot will be output, see SUN/256.

                * swing:  Plot  will be displayed in a window on the screen. This plot is "live";
                  it can be resized and (except for old-style plots) navigated around with  mouse
                  actions in the same way as plots in TOPCAT.

                * out:  Plot  will  be  written  to a file given by out using the graphics format
                  given by ofmt.

                * cgi: Plot will be written in a way suitable for  CGI  use  direct  from  a  web
                  server.  The  output  is  in  the  graphics format given by ofmt, preceded by a
                  suitable "Content-type" declaration.

                * discard: Plot is drawn, but discarded. There is no output.

                * auto: Behaves as swing or out mode depending on presence of out parameter

              Determines the way that data is accessed when constructing the plot. There are  two
              basic options, cached or not.

              If  no  caching is used (simple) then rows are read sequentially from the specified
              input table(s) every time they are required. This generally requires a small memory
              footprint (though that can depend on how the table is specified) and makes sense if
              the data only needs to be scanned once or perhaps if the table is very large.

              If caching is used (cache) then the required data is read once from  the  specified
              input  table(s)  and  cached  before  any plotting is performed, and plots are done
              using this cached data. This may use a  significant  amount  of  memory  for  large
              tables  but it's usually more sensible (faster) if the data will need to be scanned
              multiple times.

              The default value is cache if a live plot is being generated  (omode=swing),  since
              in  that  case  the  plot  needs  to  be  redrawn every time the user performs plot
              navigation actions or resizes the window, or  if  animations  are  being  produced.
              Otherwise (e.g. output to a graphics file) the default is simple.

              Contains  a  comma-separated list of layer suffixes to determine the order in which
              layers are drawn on the plot. This can affect which symbol are plotted on  top  of,
              and so potentially obscure, which other ones.

              When  specifying  a  plot,  multiple  layers may be specified, each introduced by a
              parameter layer<N>, where <N> is  a  different  (arbitrary)  suffix  labelling  the
              layer, and is appended to all the parameters specific to defining that layer.

              By  default  the  layers  are  drawn  on  the plot in the order in which the layer*
              parameters appear on the command line. However if this parameter is specified, each
              comma-separated  element  is interpreted as a layer suffix, giving the ordered list
              of layers to plot. Every element of the list must be a suffix with a  corresponding
              layer parameter, but missing or repeated elements are allowed.

              Whether  to  draw  a  legend  or not. If no value is supplied, the decision is made
              automatically: a legend is drawn only if it would have more than one entry.

              If true, a line border is drawn around the legend.

              If true, the background of the legend is opaque, and the legend obscures  any  plot
              components behind it. Otherwise, it's transparent.

              Determines  which  layers  are  represented in the legend (if present) and in which
              order they appear. The legend has a line for each layer label (as determined by the
              leglabelN  parameter). If multiple layers have the same label, they will contribute
              to the same entry in the legend, with style icons  plotted  over  each  other.  The
              value  of  this  parameter  is  a comma-separated sequence of layer suffixes, which
              determines the order in which the  legend  entries  appear.  Layers  with  suffixes
              missing from this list do not show up in the legend at all.

              If  no  value  is  supplied  (the  default),  the sequence is the same as the layer
              plotting sequence (see seq).

              Determines the internal position of the legend on the plot. The value is  a  comma-
              separated  pair  of  values  giving  the X and Y positions of the legend within the
              plotting bounds, so for instance "0.5,0.5" will put the legend right in the  middle
              of  the  plot.  If  no  value  is supplied, the legend will appear outside the plot

              Text of a title to be displayed at the top of the plot. If null,  the  default,  no
              title is shown and there's more space for the graphics.

              Color map used for Aux axis shading.

              A  mixed  bag  of  colour  ramps  are  available:  inferno, magma, plasma, viridis,
              cubehelix, sron, rainbow, rainbow2, rainbow3, pastel,  accent,  gnuplot,  gnuplot2,
              specxby,  set1,  paired,  hotcold,  rdbu,  piyg, brbg, cyan-magenta, red-blue, brg,
              heat, cold, light, greyscale, colour,  standard,  bugn,  bupu,  orrd,  pubu,  purd,
              huecl,  hue,  intensity,  rgb_red, rgb_green, rgb_blue, hsv_h, hsv_s, hsv_v, yuv_y,
              yuv_u,  yuv_v,  scale_hsv_s,  scale_hsv_v,  scale_yuv_y,  mask,  blacker,   whiter,
              transparency. Note: many of these, including rainbow-like ones, are frowned upon by
              the visualisation community.

              You can also construct your own custom colour map by giving a  sequence  of  colour
              names  separated  by minus sign ("-") characters. In this case the ramp is a linear
              interpolation between each pair of colours named, using the  same  syntax  as  when
              specifying  a  colour  value.  So for instance "yellow-hotpink-#0000ff" would shade
              from yellow via hot pink to blue.

              Defines a subrange of the colour ramp to be used for  Aux  shading.  The  value  is
              specified as a (low,high) comma-separated pair of two numbers between 0 and 1.

              If the full range 0,1 is used, the whole range of colours specified by the selected
              shader will be used. But if for instance a value of  0,0.5  is  given,  only  those
              colours at the left hand end of the ramp will be seen.

              If  the null (default) value is chosen, a default clip will be used. This generally
              covers most or all of the range 0-1 but for colour maps  which  fade  to  white,  a
              small  proportion  of the lower end may be excluded, to ensure that all the colours
              are visually distinguishable from a white background. This  default  is  usually  a
              good idea if the colour map is being used with something like a scatter plot, where
              markers are plotted against a white  background.  However,  for  something  like  a
              density map when the whole plotting area is tiled with colours from the map, it may
              be better to supply the whole range 0,1 explicitly.

              If true, the colour map on the Aux axis will be reversed.

              Allows the colour map used for the Aux axis to be quantised. If an integer value  N
              is chosen then the colour map will be viewed as N discrete evenly-spaced levels, so
              that only N different colours will appear in the plot. This can be used to generate
              a contour-like effect, and may make it easier to trace the boundaries of regions of
              interest by eye.

              If left blank, the colour map is nominally continuous (though in practice it may be
              quantised to a medium-sized number like 256).

              Defines  the  way  that  values  in the Aux range are mapped to the selected colour

              The available options are:

                * log: Logarithmic scaling

                * linear: Linear scaling

                * sqrt: Square root scaling

                * square: Square scaling

              Minimum value of the data coordinate on the Aux axis. This sets  the  value  before
              any  subranging  is  applied.  If  not  supplied,  the value is determined from the
              plotted data.

              Maximum value of the data coordinate on the Aux axis. This sets  the  value  before
              any  subranging  is  applied.  If  not  supplied,  the value is determined from the
              plotted data.

              Sets the label used to annotate the aux axis, if it is visible.

              Determines how closely the tick marks are spaced on the Aux axis, if  visible.  The
              default  value  is  1, meaning normal crowding. Larger values result in more ticks,
              and smaller values fewer ticks. Tick marks will not however be  spaced  so  closely
              that  the  labels  overlap  each other, so to get very closely spaced marks you may
              need to reduce the font size as well.

              Determines the lateral size of the aux colour ramp, if visible, in pixels.

              Determines whether the aux axis colour ramp is displayed alongside the plot.

              If not supplied (the default), the aux axis will be visible  when  aux  shading  is
              used in any of the plotted layers.

              Affects  whether  rendering  of the data contents of a plot (though not axis labels
              etc) is always done to an intermediate bitmap rather than,  where  possible,  being
              painted  using  graphics  primitives.  This  is  a  rather  arcane setting that may
              nevertheless have noticeable effects on  the  appearance  and  size  of  an  output
              graphics file, as well as plotting time. For some types of plot (e.g. shadingN=auto
              or shadingN=density) it will have no effect, since this kind of  rendering  happens
              in any case.

              When  writing to vector graphics formats (PDF and PostScript), setting it true will
              force the data contents to be bitmapped. This may make the  output  less  beautiful
              (round  markers  will  no  longer  be perfectly round), but it may result in a much
              smaller file if there are very many data points.

              When writing to bitmapped output formats (PNG, GIF, JPEG, ...), it fixes shapes  to
              be  the  same  as  seen  on  the screen rather than be rendered at the mercy of the
              graphics system, which sometimes introduces small distortions.

              Defines how multiple overplotted partially transparent pixels are combined to  form
              a  resulting  colour.  The way this is used depends on the details of the specified

              Currently, this parameter takes a "boost" value in the range 0..1. If the value  is
              zero,  saturation semantics are used: RGB colours are added in proporition to their
              associated alpha value until the total alpha is saturated (reaches 1), after  which
              additional  pixels  have  no further effect. For larger boost values, the effect is
              similar, but any non-zero alpha in the output  is  boosted  to  the  given  minimum
              value.  The  effect  of  this  is  that  even very slightly populated pixels can be
              visually distinguished from  unpopulated  ones  which  may  not  be  the  case  for
              saturation composition.

              If  not  null,  this  parameter  causes  the  command to create a sequence of plots
              instead of just one. The parameter value is a table with one row for each frame  to
              be  produced.  Columns  in  the  table are interpreted as parameters which may take
              different values for each frame; the column name is the  parameter  name,  and  the
              value  for  a  given  frame  is  its  value  from  that row. Animating like this is
              considerably more efficient than invoking the STILTS command in a loop.

              The location of the animation control table. This may take  one  of  the  following

                * A filename.

                * A URL.

                * The  special  value  "-", meaning standard input. In this case the input format
                  must be given explicitly using the afmt parameter. Note that  not  all  formats
                  can be streamed in this way.

                * A  system  command  line  with  either  a  "<" 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
               In any case, compressed data in one of the supported  compression  formats  (gzip,
              Unix compress or bzip2) will be decompressed transparently.

              Specifies  the  format  of  the  animation  control table as specified by parameter
              animate. The known formats are listed in SUN/256. 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.

              If set true, the animation control table specified by the animate parameter will be
              read  as  a  stream.  It  is  necessary  to  give  the afmt 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

              Specifies processing to be performed on the animation control table as specified by
              parameter animate, before any other processing has taken place. The value  of  this
              parameter  is one or more of the filter commands described in SUN/256. 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, and lines which are blank or which start with
              a '#' character are ignored.

              Determines  how  many  threads  will  run  in parallel if animation output is being
              produced. Only used if the animate parameter is supplied. The default value is  the
              number of processors apparently available to the JVM.

              Sky projection used to display the plot.

              The available options are:

                * sin: rotatable sphere

                * aitoff: Hammer-Aitoff projection

                * car: Plate Carree projection (lon/lat on Cartesian axes)

              The sky coordinate system used for the generated plot.

              Choice  of  this  value  goes  along  with  the  data coordinate system that may be
              specified for plot layers. If unspecified, a generic longitude/latitude  system  is
              used,  and  all lon/lat coordinates in the plotted data layers are assumed to be in
              the same system. If a value is supplied for this parameter, then a sky system  must
              (implicitly or explicitly) be supplied for each data layer, and the coordinates are
              converted from data to view system before being plotted.

              The available options are:

                * equatorial: J2000 equatorial system

                * galactic: IAU 1958 galactic system

                * supergalactic: De Vaucouleurs supergalactic system

                * ecliptic: ecliptic system based on conversion at 2000.0

              Whether to invert the celestial sphere by displaying the longitude axis  increasing
              right-to-left  rather  than  left-to-right.  It  is  conventional  to  display  the
              celestial sphere in this way because that's what it looks like from the  earth,  so
              the default is true. Set it false to see the sphere from the outside.

              If  true,  sky  coordinate  grid  lines  are  drawn on the plot. If false, they are

              Controls whether and  where  the  numeric  annotations  of  the  lon/lat  axes  are
              displayed.  The  default  option  Auto  usually  does the sensible thing, but other
              options exist to force labelling internally or externally to the plot region, or to
              remove numeric labels altogether.

              The available options are:

                * Auto:  Uses  External or Internal policy according to whether the sky fills the
                  plot bounds or not

                * External: Labels are drawn outside the plot bounds

                * Internal: Labels are drawn inside the plot bounds

                * Basic: Labels are drawn somewhere near the grid line

                * Hybrid: Grid lines are labelled outside the plot  bounds  where  possible,  but
                  inside if they would otherwise be invisible

                * None: Axes are not labelled

              If  true, grid line labels are written in sexagesimal notation, if false in decimal

              Determines how closely sky grid lines are spaced. The default value is  1,  meaning
              normal  crowding.  Larger  values  result in more grid lines, and smaller values in
              fewer grid lines.

              The color of the plot grid, 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.

              The color of axis labels and  other  plot  annotations,  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.

              If  true,  grid lines are drawn with antialiasing. Antialiased lines look smoother,
              but may take perceptibly longer to draw. Only has any effect for  bitmapped  output

              Determines  how to turn label text into characters on the plot. 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

              Size of the text font in points.

              Font style for text.

              The available options are:

                * standard

                * serif

                * mono

              Font weight for text.

              The available options are:

                * plain

                * bold

                * italic

                * bold_italic

              Longitude of the central position of the plot in decimal degrees. Use with clat and
              radius.  If  the  center is not specified, the field of view is determined from the

              Latitude of the central position of the plot in decimal degrees. Use with clon  and
              radius.  If  the  center is not specified, the field of view is determined from the

              Approximate radius of the plot field of view in degrees. Only used if clon and clat
              are also specified.

              Sets the amount by which the plot view zooms in or out for each unit of mouse wheel
              movement. A value of 1 means that mouse wheel zooming has no effect. A higher value
              means that the mouse wheel zooms faster and a value nearer 1 means it zooms slower.
              Values below 1 are not permitted.

              Sets the presentation label for the layer with a given suffix.  This  is  the  text
              which  is  displayed  in  the  legend, if present. Multiple layers may use the same
              label, in which case they will be combined to form a single legend entry.

              If no value is supplied (the default), the suffix itself is used as the label.

       layerN=<layer-type> <layerN-specific-params>
              Selects one of the available plot types for layerN. A plot consists of  a  plotting
              surface,  set  up  using the various unsuffixed parameters of the plotting command,
              and zero or more plot layers. Each layer is introduced by a parameter with the name
              layer<N> where the suffix "<N>" is a label identifying the layer and is appended to
              all the parameter names which configure that layer. Suffixes  may  be  any  string,
              including the empty string.

              This  parameter  may  take one of the following values, described in more detail in

                * mark

                * size

                * sizexy

                * skyvector

                * skyellipse

                * skycorr

                * link2

                * mark2

                * label

                * contour

                * skydensity

                * healpix

                * skygrid

              Each of these layer types comes with a list of type-specific parameters  to  define
              the details of that layer, including some or all of the following groups:

                * input table parameters (e.g. inN, icmdN)

                * coordinate params referring to input table columns (e.g. xN, yN)

                * layer style parameters (e.g. shadingN, colorN)

              Every parameter notionally carries the same suffix N. However, if the suffix is not
              present, the application will try looking for a parameter with the same  name  with
              no  suffix  instead. In this way, if several layers have the same value for a given
              parameter (for instance input table),  you  can  supply  it  using  one  unsuffixed
              parameter  to  save  having  to  supply  several parameters with the same value but
              different suffixes.



       If the package stilts-doc is installed, the full documentation  SUN/256  is  available  in
       HTML format:


       STILTS version 3.1-5-debian

       This  is  the  Debian  version  of Stilts, which lack the support of some file formats and
       network protocols. For differences see


       Mark Taylor (Bristol University)

                                             Mar 2017                          STILTS-PLOT2SKY(1)