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)