bionic (3) plmap.3plplot.gz

NAME

       plmap - Plot continental outline or shapefile data in world coordinates

SYNOPSIS

       plmap(mapform, name, minx, maxx, miny, maxy)

DESCRIPTION

       Plots  continental  outlines  or  shapefile data in world coordinates. A demonstration of how to use this
       function to create different projections can be found in examples/c/x19c. PLplot is provided  with  basic
       coastal  outlines  and  USA state borders. These can be used irrespective of whether Shapefile support is
       built into PLplot. With Shapefile support this function can also be used with user Shapefiles,  in  which
       case  it will plot the entire contents of a Shapefile joining each point of each Shapefile element with a
       line. Shapefiles have become a popular standard for geographical data and data  in  this  format  can  be
       easily  found from a number of online sources. Shapefile data is actually provided as three or more files
       with the same filename, but different extensions. The .shp and  .shx  files  are  required  for  plotting
       Shapefile data with PLplot.

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

       This function is used in example 19.

ARGUMENTS

       mapform (PLMAPFORM_callback(3plplot), input)
              A  user  supplied  function  to  transform  the  original map data coordinates to a new coordinate
              system. The PLplot-supplied map data is provided as latitudes and longitudes; other Shapefile data
              may  be  provided  in other coordinate systems as can be found in their .prj plain text files. For
              example, by using this transform we can change from a longitude, latitude coordinate  to  a  polar
              stereographic  projection.  Initially,  x[0]..[n-1] are the original x coordinates (longitudes for
              the PLplot-supplied data) and y[0]..y[n-1] are the corresponding y coordinates (latitudes for  the
              PLplot  supplied  data).   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 type of map plotted. This is either  one  of  the  PLplot
              built-in  maps  or  the file name of a set of Shapefile files without the file extensions. For the
              PLplot built-in maps the possible values are: "globe" -- continental outlines  "usa"  --  USA  and
              state  boundaries  "cglobe"  --  continental  outlines  and  countries  "usaglobe"  --  USA, state
              boundaries and continental outlines

       minx (PLFLT(3plplot), input)
              The minimum x value of map elements to be drawn. For the built  in  maps  this  is  a  measure  of
              longitude. For Shapefiles the units must match the projection. The value of minx must be less than
              the value of maxx. Specifying a useful limit for these limits provides a useful  optimization  for
              complex or detailed maps.

       maxx (PLFLT(3plplot), input)
              The maximum x value of map elements to be drawn

       miny (PLFLT(3plplot), input)
              The  minimum  y  value  of  map  elements  to be drawn. For the built in maps this is a measure of
              latitude. For Shapefiles the units must match the projection. The value of miny must be less  than
              the value of maxy.

       maxy (PLFLT(3plplot), input)
              The maximum y value of map elements to be drawn.

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                                   PLMAP(3plplot)