NAME

       plcalc_world  -  Calculate  world coordinates and corresponding window index from relative
       device coordinates

SYNOPSIS

       plcalc_world(rx, ry, wx, wy, window)

DESCRIPTION

       Calculate world coordinates, wx and wy,  and  corresponding  window  index  from  relative
       device coordinates, rx and ry.

       Redacted form:  General: plcalc_world(rx, ry, wx, wy, window) Perl/PDL: Not available?

       This function is used in example 31.

ARGUMENTS

       rx (PLFLT, input)
              Input relative device coordinate (ranging from 0. to 1.) for the x coordinate.

       ry (PLFLT, input)
              Input relative device coordinate (ranging from 0. to 1.) for the y coordinate.

       wx (PLFLT *, output)
              Pointer to the returned world coordinate for x corresponding to the relative device
              coordinates rx and ry.

       wy (PLFLT *, output)
              Pointer to the returned world coordinate for y corresponding to the relative device
              coordinates rx and ry.

       window (PLINT *, output)
              Pointer  to  the  returned  last defined window index that corresponds to the input
              relative device coordinates (and the returned world  coordinates).   To  give  some
              background  on  the  window index, for each page the initial window index is set to
              zero, and each time plwind(3plplot) is called within the  page,  world  and  device
              coordinates  are  stored for the window and the window index is incremented.  Thus,
              for a simple  page  layout  with  non-overlapping  viewports  and  one  window  per
              viewport,  window  corresponds  to  the  viewport  index  (in  the  order which the
              viewport/windows were created) of the only viewport/window corresponding to rx  and
              ry.   However,  for more complicated layouts with potentially overlapping viewports
              and possibly more than one window (set of world coordinates) per  viewport,  window
              and  the  corresponding  output  world  coordinates  corresponds to the last window
              created that fulfills the criterion that the relative device coordinates are inside
              it.   Finally,  in  all  cases  where the input relative device coordinates are not
              inside any viewport/window, then window is set to -1.

AUTHORS

       Many developers  (who  are  credited  at  http://plplot.sourceforge.net/credits.php)  have
       contributed to PLplot over its long history.

SEE ALSO

       PLplot documentation at http://plplot.sourceforge.net/documentation.php.

                                          February, 2016                    PLCALC_WORLD(3plplot)