Provided by: stilts_3.4.9-5_all bug

NAME

       stilts-plot2sky - Draws a sky plot

SYNOPSIS


       stilts plot2sky [xpix=<int-value>] [ypix=<int-value>] [insets=<top>,<left>,<bottom>,<right>]
                       [omode=swing|out|cgi|discard|auto] [storage=simple|memory|disk|policy|cache|basic-
                       cache|persistent|parallel] [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|histogram|histolog|sqrt|square|acos|cos] [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>]
                       [projection=sin|aitoff|aitoff0|car|car0]
                       [viewsys=equatorial|galactic|supergalactic|ecliptic] [reflectlon=true|false]
                       [grid=true|false] [scalebar=true|false] [labelpos=Auto|External|Internal|...]
                       [sex=true|false] [crowd=<number>] [gridcolor=<rrggbb>|red|blue|...] [gridtrans=0..1]
                       [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>]

DESCRIPTION

       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  ap‐
       proximates  to a tangent projection for small regions of the sky), but Hammer-Aitoff and Plate Carée pro‐
       jections 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 sys‐
       tems e.g.: plot2sky viewsys=galactic layer1=mark in1=cat.fits lon1=RA2000 lat1=DEC2000 datasys1=equatori‐
       al

       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,  poly4,  mark4,  polygon,  area, central, label, arealabel, contour, skydensity,
       healpix, skygrid.

OPTIONS

       xpix=<int-value>
              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 insets.

       ypix=<int-value>
              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 insets.

       insets=<top>,<left>,<bottom>,<right>
              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 border.

              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.

       omode=swing|out|cgi|discard|auto
              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 re‐
                  sized 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

       storage=simple|memory|disk|policy|cache|basic-cache|persistent|parallel
              Determines the way that data is accessed when constructing the plot. There are two  main  options,
              cached  or not. If no caching is used then rows are read sequentially from the specified input ta‐
              ble(s) every time they are required. This generally requires a small  resource  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 then the required  data  is
              read  once from the specified input table(s), then prepared and cached before any plotting is per‐
              formed, and plots are done using this cached data. This may use a significant  amount  of  storage
              for  large tables but it's usually more sensible (faster) if the data will need to be scanned mul‐
              tiple times. There are various options for cache storage.

              The options are:

                * simple: no caching, data read directly from input table

                * memory: cached to memory; OutOfMemoryError possible for very large plots

                * disk: cached to disk

                * policy: cached using application-wide default storage policy, which is usually adaptive (memo‐
                  ry/disk hybrid)

                * persistent: cached to persistent files on disk, in the system temporary directory (defined  by
                  system  property  java.io.tmpdir).  If this is used, plot data will be stored on disk in a way
                  that means they can be re-used between STILTS invocations, so data preparation can be  avoided
                  on subsequent runs. Note however it can leave potentially large files in your temporary direc‐
                  tory.

                * cache: synonym for memory (backward compatibility)

                * basic-cache: dumber version of memory (no optimisation for constant-valued columns)

                * parallel: experimental version of memory-based cache that reads into the cache in parallel for
                  large  files.  This  will make the plot faster to prepare, but interaction is a bit slower and
                  sequence-dependent attributes of the plot may not come out right. This experimental option may
                  be withdrawn or modified in future releases.

              The default value is memory 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  de‐
              fault is simple.

       seq=<suffix>[,...]
              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 para‐
              meters 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 inter‐
              preted 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 al‐
              lowed.

       legend=true|false
              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.

       legborder=true|false
              If true, a line border is drawn around the legend.

       legopaque=true|false
              If  true,  the background of the legend is opaque, and the legend obscures any plot components be‐
              hind it. Otherwise, it's transparent.

       legseq=<suffix>[,...]
              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  suf‐
              fixes, 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).

       legpos=<xfrac,yfrac>
              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 boundary.

       title=<value>
              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.

       auxmap=<map-name>|<color>-<color>[-<color>...]
              Color map used for Aux axis shading.

              A mixed bag of colour ramps are available as listed in SUN/256: inferno, magma,  plasma,  viridis,
              cividis,  cubehelix, sron, rainbow, rainbow2, rainbow3, pastel, cosmic, ember, gothic, rainforest,
              voltage, bubblegum, gem, chroma, neon, tropical, accent, gnuplot, gnuplot2, specxby, set1, paired,
              hotcold, guppy, iceburn, redshift, pride, rdbu, piyg, brbg,  cyan-magenta,  red-blue,  brg,  heat,
              cold,  light, greyscale, colour, standard, bugn, bupu, orrd, pubu, purd, painbow, huecl, infinity,
              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  "yel‐
              low-hotpink-#0000ff" would shade from yellow via hot pink to blue.

       auxclip=<lo>,<hi>
              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 back‐
              ground. 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.

       auxflip=true|false
              If true, the colour map on the Aux axis will be reversed.

       auxquant=<number>
              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 easi‐
              er 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).

       auxfunc=log|linear|histogram|histolog|sqrt|square|acos|cos
              Defines the way that values in the Aux range are mapped to the selected colour ramp.

              The available options are:

                * log: Logarithmic scaling

                * linear: Linear scaling

                * histogram: Scaling follows data distribution, with linear axis

                * histolog: Scaling follows data distribution, with logarithmic axis

                * sqrt: Square root scaling

                * square: Square scaling

                * acos: Arccos Scaling

                * cos: Cos Scaling

              For all these options, the full range of data values is used, and displayed on the colour  bar  if
              applicable. The Linear, Log, Square and Sqrt options just apply the named function to the full da‐
              ta  range.  The histogram options on the other hand use a scaling function that corresponds to the
              actual distribution of the data, so that there are about the same number of points (or pixels,  or
              whatever  is  being scaled) of each colour. The histogram options are somewhat more expensive, but
              can be a good choice if you are exploring data whose distribution is unknown or  not  well-behaved
              over  its  min-max  range.  The Histogram and HistoLog options both assign the colours in the same
              way, but they display the colour ramp with linear or logarithmic annotation respectively; the His‐
              toLog option also ignores non-positive values.

       auxmin=<number>
              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.

       auxmax=<number>
              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.

       auxlabel=<text>
              Sets the label used to annotate the aux axis, if it is visible.

       auxcrowd=<factor>
              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.

       auxwidth=<pixels>
              Determines the lateral size of the aux colour ramp, if visible, in pixels.

       auxvisible=true|false
              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.

       forcebitmap=true|false
              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 primi‐
              tives. This is a rather arcane setting that may nevertheless have noticeable effects  on  the  ap‐
              pearance  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 hap‐
              pens 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.

       compositor=0..1
              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 plot.

              Currently, this parameter takes a "boost" value in the range 0..1. If the value is  zero,  satura‐
              tion  semantics are used: RGB colours are added in proporition to their associated alpha value un‐
              til the total alpha is saturated (reaches 1), after which additional pixels have  no  further  ef‐
              fect.  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  com‐
              position.

       animate=<table>
              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 forms:

                * A filename.

                * A URL.

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

                * A scheme specification of the form :<scheme-name>:<scheme-args>.

                * 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 systems.
               In any case, compressed data in one of the supported compression formats (gzip, Unix compress  or
              bzip2) will be decompressed transparently.

       afmt=<in-format>
              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  pro‐
              gram  will  exit  with an error explaining which formats were attempted. This parameter is ignored
              for scheme-specified tables.

       astream=true|false
              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 opera‐
              tions 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.

       acmd=<cmds>
              Specifies processing to be performed on the animation control table as specified by parameter ani‐
              mate, 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.

       parallel=<int-value>
              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.

       projection=sin|aitoff|aitoff0|car|car0
              Sky projection used to display the plot.

              The available options are:

                * sin: rotatable sphere

                * aitoff: Hammer-Aitoff projection with lon=0 at center

                * aitoff0: Hammer-Aitoff projection with lon=180 at center

                * car: Plate Carree projection (lon/lat on Cartesian axes) with lon=0 at center

                * car0: Plate Carree Projection (lon/lat on Cartesian axes) with lon=180 at center

              Note  that  for  historical  reasons  the projections named "aitoff" denote the equal-area Hammer-
              Aitoff projection and not the Aitoff projection itself. The Hammer-Aitoff  projection  is  defined
              as:

                * x = [2sqrt(2)/sqrt(1+cos(lat)cos(lon/2))]cos(lat)sin(lon/2)

                * y = [sqrt(2)/sqrt(1+cos(lat)cos(lon/2))]sin(lat)

       viewsys=equatorial|galactic|supergalactic|ecliptic
              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

       reflectlon=true|false
              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.

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

       scalebar=true|false
              If true, a small bar is drawn near the bottom left of the plot annotated with a  distance  in  de‐
              grees, arc minutes or arc seconds, to make it easier to determine the size of features on the plot
              by eye.

       labelpos=Auto|External|Internal|...
              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

                * ExternalSys: Like External, but the axes are also labelled with coordinate system axis names

                * InternalSys: Like Internal, but the axes are also labelled with coordinate system axis names

              The ExternalSys and InternalSys options use axis descriptions appropriate to the  View  coordinate
              system for the current plot; these options may not work well for plots which are all-sky or show a
              substantial proportion of the sky.

       sex=true|false
              If true, grid line labels are written in sexagesimal notation, if false in decimal degrees.

       crowd=<number>
              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.

       gridcolor=<rrggbb>|red|blue|...
              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, yel‐
              low, 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 magen‐
              ta.

       gridtrans=0..1
              Transparency  of grid lines that may be drawn over the plot. The range is 0 (opaque) to 1 (invisi‐
              ble). This value is 1-alpha.

       labelcolor=<rrggbb>|red|blue|...
              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,  yel‐
              low, 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 magen‐
              ta.

       gridaa=true|false
              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 formats.

       texttype=plain|antialias|latex
              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 bug).

       fontsize=<int-value>
              Size of the text font in points.

       fontstyle=standard|serif|mono
              Font style for text.

              The available options are:

                * standard

                * serif

                * mono

       fontweight=plain|bold|italic|bold_italic
              Font weight for text.

              The available options are:

                * plain

                * bold

                * italic

                * bold_italic

       clon=<degrees>
              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 data.

       clat=<degrees>
              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 data.

       radius=<degrees>
              Approximate radius of the plot field of view in degrees. Only used if clon and clat are also spec‐
              ified.

       zoomfactor=<number>
              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.

       leglabelN=<text>
              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 com‐
              bined 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. Suf‐
              fixes may be any string, including the empty string.

              This parameter may take one of the following values, described in more detail in SUN/256:

                * mark

                * size

                * sizexy

                * skyvector

                * skyellipse

                * skycorr

                * link2

                * mark2

                * poly4

                * mark4

                * polygon

                * area

                * central

                * label

                * arealabel

                * 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.

SEE ALSO

       stilts(1)

       If the package stilts-doc is installed, the full documentation SUN/256 is available in HTML format:
       file:///usr/share/doc/stilts/sun256/index.html

VERSION

       STILTS version 3.4.9-debian

       This  is the Debian version of Stilts, which lack the support of some file formats and network protocols.
       For differences see
       file:///usr/share/doc/stilts/README.Debian

AUTHOR

       Mark Taylor (Bristol University)

                                                    Mar 2017                                  STILTS-PLOT2SKY(1)