bionic (3) plmapline.3plplot.gz

Provided by: plplot-doc_5.13.0+dfsg-6ubuntu2_all bug

NAME
       plmapline - Plot all or a subset of Shapefile data using lines in world coordinates


SYNOPSIS
       plmapline(mapform, name, minx, maxx, miny, maxy, plotentries, nplotentries)


DESCRIPTION
       Plot  all  or  a  subset  of  Shapefile  data using lines in world coordinates. Our 19th standard example
       demonstrates how to use this function. This function plots data  from  a  Shapefile  using  lines  as  in
       plmap(3plplot),  however  it  also  has  the  option  of  also  only  drawing specified elements from the
       Shapefile. The vector of indices of the  required  elements  are  passed  as  a  function  argument.  The
       Shapefile  data  should  include  a metadata file (extension.dbf) listing all items within the Shapefile.
       This file can be opened by most popular spreadsheet programs and can be used to decide which  indices  to
       pass to this function.

       Redacted form: plmapline(mapform, name, minx, maxx, miny, maxy, plotentries)

       This function is used in example 19.


ARGUMENTS
       mapform (PLMAPFORM_callback(3plplot), input)
              A  user  supplied  function  to  transform  the  coordinates  given  in  the shapefile into a plot
              coordinate system. By using this transform, we can change from a longitude, latitude coordinate to
              a  polar  stereographic  project,  for  example.   Initially,  x[0]..[n-1]  are the longitudes and
              y[0]..y[n-1] are the corresponding latitudes.  After the call to mapform(), x[] and y[] should  be
              replaced  by  the  corresponding  plot  coordinates.  If  no  transform is desired, mapform can be
              replaced by NULL.

       name (PLCHAR_VECTOR(3plplot), input)
              An ascii character string specifying the file name of a set of Shapefile files  without  the  file
              extension.

       minx (PLFLT(3plplot), input)
              The  minimum  x  value to be plotted. This must be in the same units as used by the Shapefile. You
              could use a very large negative number to plot everything, but  you  can  improve  performance  by
              limiting  the area drawn. The units must match those of the Shapefile projection, which may be for
              example longitude or distance. The value of minx must be less than the value of maxx.

       maxx (PLFLT(3plplot), input)
              The maximum x value to be plotted. You could use a very large number to plot everything,  but  you
              can improve performance by limiting the area drawn.

       miny (PLFLT(3plplot), input)
              The  minimum  y  value to be plotted. This must be in the same units as used by the Shapefile. You
              could use a very large negative number to plot everything, but  you  can  improve  performance  by
              limiting  the area drawn. The units must match those of the Shapefile projection, which may be for
              example latitude or distance. The value of miny must be less than the value of maxy.

       maxy (PLFLT(3plplot), input)
              The maximum y value to be plotted. You could use a very large number to plot everything,  but  you
              can improve performance by limiting the area drawn.

       plotentries (PLINT_VECTOR(3plplot), input)
              A  vector containing the zero-based indices of the Shapefile elements which will be drawn. Setting
              plotentries to NULL will plot all elements of the Shapefile.

       nplotentries (PLINT(3plplot), input)
              The number of items in plotentries.  Ignored if plotentries is NULL.


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.

                                                 November, 2017                               PLMAPLINE(3plplot)