NAME

       gvmap - find clusters and create a geographical map highlighting clusters.

SYNOPSIS

       gvmap [ options ] [ -o outfile ] [ files ]

DESCRIPTION

       gvmap  takes  as input a graph in DOT format, finds node clusters and produces a rendering
       of the graph as a geographic-style map, with clusters highlighted as  countries,  in  xdot
       format.

       In the input graph, each node must have position, width and height information (pos, width
       and height attributes, respectively) defined, and nodes must not overlap.

       By default, gvmap will generate the clusters from the data. If desired,  the  input  graph
       can  specify cluster information by giving every node a cluster attribute whose value is a
       small positive integer. (It is works best if  cluster  values  are  all  integers  in  the
       interval [1,K] for some K. Nodes sharing the same cluster attribute value will be put into
       the same cluster. N.B. For the cluster attribute to be used, all nodes must have  a  valid
       value.

       If  the  -D  flag is used, gvmap will use the top-level cluster subgraphs to determine the
       clustering. Any nodes not in such a cluster will be put into a single catch-all cluster.

       If the input specifies the desired clustering as described above, it can  also  specify  a
       desired  coloring  by  having  some node in each cluster provide a clustercolor attribute.
       N.B. Unless one specifies -c0, only the clustercolor of the last node in a cluster has  an
       effect. In addition, unless one uses -O, gvmap may permute the given colors.

OPTIONS

       The following options are supported:

       -a k   The  integer  k  specifies  the average number of artificial points added along the
              bounding box of the labels. Such artificial points are added  to  avoid  a  country
              boundary  cutting  through  the  boundary  box  of  the  labels.  Computing time is
              proportional to k; hence, for large graphs, a small value of k is suggested. If k =
              -1,  a  suitable  value  of k is automatically selected based on the graph size. By
              default k = -1.

       -b v   The real number v specifies the line width used to  draw  the  polygon  boundaries,
              with v < 0 for no line. By default v = 0.

       -c k   The integer k specifies color scheme used to color the countries. By default k = 1.

          Acceptable values are:
                 0 : no polygons
                 1 : pastel
                 2 : blue to yellow
                 3 : white to red
                 4 : light grey to red
                 5 : primary colors
                 6 : sequential single hue red
                 7 : sequential single hue lighter red
                 8 : light grey

       -c_opacity=xy
              Specifies  a  two-character  hexadecimal  string  specifying  the  opacity  of  the
              polygons.

       -C d   The integer d specifies the maximum number  of  clusters  (countries)  allowed.  By
              default d = 0, which means that there is no limit.

       -d d   The  integer  d specifies the random seed used during color assignment optimization
              that maximize color difference between neighboring countries.

       -D     If specified, the graph's cluster subgraphs are used to specify the clustering.

       -e     If specified, edges will be included in the final output.

       -g c   Specifies the bounding box color. If not specified, a bounding box is not drawn.

       -h k   The number of artificial points added to maintain a bridge  between  endpoints.  By
              default, this is zero.

       -highlight=k
              Only draw cluster k. By default, all clusters are drawn.

       -k     If specified, increases the randomness of outer boundary.

       -l s   Use the string s as a label for the drawing.

       -m v   Generate a margin of v points around the drawing. By default, this is determined by
              gvmap.

       -O     Do NOT do color assignment optimization that maximizes  color  differences  between
              neighboring countries

       -o<file>
              Put output in <file>. Default output is stdout

       -p k   Indicates what level of points should be shown. By default, no points are shown.

          Acceptable values are:
                 0 : no points
                 1 : all points
                 2 : label points
                 3 : random/artificial points

       -Q     Use   modularity   quality  for  clustering  rather  than  the  default  modularity
              clustering.

       -r k   The number of random points k (integer) used to define sea and lake boundaries.  If
              0, auto assigned. By default v = 0

       -s v   The  real  number v specifies the depth of the sea and lake shores in points. If 0,
              auto assigned. By default v = 0.

       -t n   Make n attempts to improve cluster contiguity.

       -v     Verbose mode.

       -z c   Specified the polygon line color. Default is black.

       -?     Print usage and exit.

EXAMPLES

       Given a graph foo.gv, one way to generate a layout and highlight the clusters is to  first
       select  a  layout  engine  with a suitable overlap removal method, then feed the output to
       gvmap, and finally render the  map  using  specific  graphics  format.  For  example,  the
       following  pipeline creates a map with edges in semi-transparent light gray and nodes laid
       out using sfdp:

       sfdp -Goverlap=prism foo.gv | gvmap -e | neato -n2 -Ecolor=#55555522 -Tpng > foo.png

       The shell script gvmap.sh provides a shorthand for such pipelines. For example, the  above
       pipeline can be achieved using

       gvmap.sh -Ae -Ecolor=#55555522 -Tpng foo.gv > foo.png

AUTHOR

       Yifan Hu <yifanhu@yahoo.com>

SEE ALSO

       gvmap.sh(1), sfdp(1), neato(1), gvpr(1)

       E.  R.  Gansner,  Y.  Hu, S. G. Kobourov, "GMap: Visualizing graphs and clusters as maps,"
       Proc. Pacific Vis. 2010, pp. 201‐208.

                                           3 March 2011                                  GVMAP(1)