1PLMAPLINE(3plplot)                PLplot API                PLMAPLINE(3plplot)
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NAME

6       plmapline - Plot all or a subset of Shapefile data using lines in world
7       coordinates
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SYNOPSIS

10       plmapline(mapform, name, minx, maxx, miny, maxy, plotentries,  nploten‐
11       tries)
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DESCRIPTION

14       Plot  all  or  a  subset of Shapefile data using lines in world coordi‐
15       nates. Our 19th standard example demonstrates how to use this function.
16       This   function   plots  data  from  a  Shapefile  using  lines  as  in
17       plmap(3plplot), however it also has the option  of  also  only  drawing
18       specified elements from the Shapefile. The vector of indices of the re‐
19       quired elements are passed as a function argument. The  Shapefile  data
20       should include a metadata file (extension.dbf) listing all items within
21       the Shapefile. This file can be opened by most popular spreadsheet pro‐
22       grams and can be used to decide which indices to pass to this function.
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24       Redacted form: plmapline(mapform, name, minx, maxx, miny, maxy, ploten‐
25       tries)
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27       This function is used in example 19.
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ARGUMENTS

30       mapform (PLMAPFORM_callback(3plplot), input)
31              A user supplied function to transform the coordinates  given  in
32              the  shapefile  into  a  plot  coordinate  system. By using this
33              transform, we can change from a longitude,  latitude  coordinate
34              to  a  polar  stereographic  project,  for  example.  Initially,
35              x[0]..[n-1] are the longitudes and y[0]..y[n-1] are  the  corre‐
36              sponding  latitudes.   After  the call to mapform(), x[] and y[]
37              should be replaced by the corresponding plot coordinates. If  no
38              transform is desired, mapform can be replaced by NULL.
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40       name (PLCHAR_VECTOR(3plplot), input)
41              An  ascii  character string specifying the file name of a set of
42              Shapefile files without the file extension.
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44       minx (PLFLT(3plplot), input)
45              The minimum x value to be plotted. This  must  be  in  the  same
46              units as used by the Shapefile. You could use a very large nega‐
47              tive number to plot everything, but you can improve  performance
48              by  limiting  the  area drawn. The units must match those of the
49              Shapefile projection, which may be for example longitude or dis‐
50              tance. The value of minx must be less than the value of maxx.
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52       maxx (PLFLT(3plplot), input)
53              The  maximum  x  value to be plotted. You could use a very large
54              number to plot everything, but you can  improve  performance  by
55              limiting the area drawn.
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57       miny (PLFLT(3plplot), input)
58              The  minimum  y  value  to  be plotted. This must be in the same
59              units as used by the Shapefile. You could use a very large nega‐
60              tive  number to plot everything, but you can improve performance
61              by limiting the area drawn. The units must match  those  of  the
62              Shapefile  projection, which may be for example latitude or dis‐
63              tance. The value of miny must be less than the value of maxy.
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65       maxy (PLFLT(3plplot), input)
66              The maximum y value to be plotted. You could use  a  very  large
67              number  to  plot  everything, but you can improve performance by
68              limiting the area drawn.
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70       plotentries (PLINT_VECTOR(3plplot), input)
71              A vector containing the zero-based indices of the Shapefile ele‐
72              ments which will be drawn. Setting plotentries to NULL will plot
73              all elements of the Shapefile.
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75       nplotentries (PLINT(3plplot), input)
76              The number of items in plotentries.  Ignored if  plotentries  is
77              NULL.
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AUTHORS

81       Many  developers  (who  are  credited at http://plplot.org/credits.php)
82       have contributed to PLplot over its long history.
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SEE ALSO

85       PLplot documentation at http://plplot.org/documentation.php.
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89                                 January, 2023              PLMAPLINE(3plplot)
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