NAME
    Astro::SkyPlot - Create very basic sky plots

SYNOPSIS
      use Astro::SkyPlot qw/:all/; # export the markers
      my $plot = Astro::SkyPlot->new(); # use defaults (see below)
  
      # specify options yourself:
      $plot = Astro::SkyPlot->new(
        xsize       => 200, # mm
        ysize       => 200,
        bgcolor     => [0, 0, 0], # RGB => black
        projection  => 'hammer',
        axiscolor   => [100, 100, 100], # RGB => grey
      );
  
      $plot->setcolor(255, 0, 0); # RGB => red
      $plot->plot_lat_long(1, 1); # units: radians
      $plot->plot_lat_long(1, 1, size => 0.2, marker => MARK_CIRCLE); # units: radians, radians, mm
      $plot->write(file => "skyplot.eps");

DESCRIPTION
    A module to create very basic sky plots as EPS documents.

MARKERS
    There are multiple types of markers that can be plotted into the sky
    plot. These are defined through constants that can be exported from the
    module:

      MARK_CIRCLE           => circular markers
      MARK_CIRCLE_FILLED    => filled circular markers
      MARK_BOX              => square markers
      MARK_BOX_FILLED       => filled square markers
      MARK_TRIANGLE         => triangularmarkers
      MARK_TRIANGLE_FILLED  => filled triangular markers
      MARK_DTRIANGLE        => downward triangular markers
      MARK_DTRIANGLE_FILLED => filled downward triangular markers
      MARK_CROSS            => cross shaped markers
      MARK_DIAGCROSS        => diagonal cross shaped markers

METHODS
  new
    Constructor. Without arguments, uses the default settings (cf.
    SYNOPSIS). Supports the following options:

        xsize       => Plot x-size in mm (def: 200mm)
        ysize       => Plot y-size in mm (def: 200mm)
        bgcolor     => Background color as array reference
                       (RGB value 0-255 per component)
                       (def: black, [0, 0, 0])
        projection  => Projection type. Default: Hammer projection ('hammer')
        axiscolor   => Color for the axes. (def: grey, [100, 100, 100])

  setcolor
    Set a new drawing color. Takes three numbers corresponding to red, green
    and blue values between 0 and 255.

  plot_lat_long
    Draw a new latitude/longitude point.

    These may be followed by key/value pairs of options. Supported options:

    "size": the size (radius) of the point (default: 0.1mm)

    "marker": The type of marker to use (see "MARKERS").

  write
    Write the plot to the specified EPS file.

ACCESSOR METHODS
    The following are read only accessors unless otherwise noted.

  marker
    Get/Set the default marker type. The marker type for a single plot
    operation can be specified as an option to "plot_lat_long".

  ps
    Returns the internals "PostScript::Simple" object.

  xsize
    Returns the image's width (in mm).

  ysize
    Returns the image's height (in mm).

PRIVATE METHODS
  _draw_bg
    Draws the plot's background.

  _restore_color
    Restores the previously saved color.

  _plot_axis
    Plot the sky-plot axis.

  _project
    Projects given lat/long to x/y to plot coordinates.

  _draw_marker
    Draws a marker at the given plot coordinates. Arguments "$x, $y,
    $markerno, $size".

SEE ALSO
    For more general information on map projections:
    <http://en.wikipedia.org/wiki/Map_projection>

    Map projections are implemented in Astro::MapProjection

AUTHOR
    Steffen Mueller, <smueller@cpan.org>

COPYRIGHT AND LICENSE
    Copyright (C) 2009 by Steffen Mueller

    This library is free software; you can redistribute it and/or modify it
    under the same terms as Perl itself, either Perl version 5.8.0 or, at
    your option, any later version of Perl 5 you may have available.