.shp to .gmt

mac：brew install gdal
ubuntu：sudo apt-get install gdal-bin

ogr2ogr -f "GMT" Hudson_bounds.gmt  Hudson_bounds.shp

.gmt to vcs supported file

gmt2vcs_continents.py Hudson_bounds.gmt

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# gmt2vcs_continents.py 0.1
# Author: Julien VIENNE (jv@climpact.com)
# Transcription from GMT coastline files to VCS compatible coastlines file.
# For a correct use with VCS follow the instructions :
#
#      1) In a shell, call the pscoast function with your region (GMT must be
#              installed):
#             $ pscoast -M -W -Ia -R-2/5/45/51 -Df > coasts.gmt
#             -M gives an ascii output (obligatory)
#             -R specifies the region to be extracted (obligatory)
#             -D specifies the resolution (optional, default = high)
#              (f=full,h=high,i=intermediate,l=low,c=crude)
#             -W for coastlines (optional)
#             -Na for political boundaries (optional)
#             -Ia  for rivers (optional)
#              (type 'man pscoast' for more indications)
#
#      2) Apply gmt2vcs_continents.py on the coasts.gmt file as following:
#
#             $ gmt2vcs_continents.py [-o data_continent_other8] coasts.gmt
#
#             -o specifies the name of the vcs output file name
#                     This file MUST start with 'data_continent_other'
#                     Without the -o option,  default name is 'data_continent_other7'
#
#      3) Place the output file in your PCMDI_GRAPHICS folder
#
#     4) Select the user continent option in VCDAT
#             data_continent_other7 corresponds to 'User1 continents'
#             data_continent_other8 corresponds to 'User2 continents'
#             ...
#             OR
#        Use the option continent=8 in a template definition...
#-----------------------------------------------------------------------------------------------------------------------------------#
import string,getopt,sys
def help():
    man="""Convert the output of pscoast (GMT function) into VCS compatible continent file.
    
Usage:
1) In a shell, call the pscoast function (GMT must be installed):
    $ pscoast -M -W -R-2/5/45/51 -Df > coasts.gmt
    -M gives an ascii output
    -R specifies the region to be extracted
    -D specifies the resolution (f=full,h=high,i=intermediate,l=low,c=crude)
    -W for coastlines
    -N for political boundaries
    -I for rivers
    (type man pscoast for more indications)
2) Apply gmt2vcs_continents.py on the coasts.gmt file as following:
    $ gmt2vcs_continents.py -o data_continent_other8 coasts.gmt
    -o specifies the name of the vcs output file name
        This file MUST start with 'data_continent_other'
        Default name is 'data_continent_other7'
3) Place the output file in your PCMDI_GRAPHICS folder

Enjoy!
Author: Julien VIENNE (jv@climpact.com)
"""
    print man


# Function which prints polyline in output file
def print_poly(OutputFile,x,y):
    if len(x) !=0 and len(y) !=0:
        n=len(x)
        OutputFile.write('%i 1 %f %f %f %f\n'%(2*n,min(y),max(y),min(x),max(x)))
        for i in range(n):
            if (i+1)%NbPtLigne == 0 or  i==n-1:
                OutputFile.write('%f %f\n'%(y[i],x[i]))
            else:
                OutputFile.write('%f %f '%(y[i],x[i]))

# Default outpout file
OutFileName='data_continent_other7'
stderr=sys.stderr
# Get options
try:
    myopts,myargs = getopt.getopt(sys.argv[1:], 'ho:',["help"])
except getopt.GetoptError:
    print >>stderr,"ERROR [gmt2vcs_continents.py]!! Syntax error..."
    print >>stderr,"Please type 'gmt2vcs_continents.py -h' for help"
    sys.exit(1)
    
# Manage options
for myopt, myval in myopts:
    if myopt in ('-h','--help'):
        help()
        sys.exit(0)
    elif myopt == '-o':
        OutFileName=myval
        if OutFileName[:20] != 'data_continent_other':
            print >>stderr,"WARNING [gmt2vcs_continents.py]!!"
            print >>stderr,"To be compatible with VCS, outfile name must start "
            print >>stderr,"with 'data_continent_other'"
# If no input file
if len(myargs)==0:
    print >>stderr,"ERROR [gmt2vcs_continents.py]!!"
    print >>stderr,"Give a GMT coastline file name"
    print >>stderr,"Type gmt2vcs_continents.py -h for help"
    sys.exit(1)
# Open GMT file
try:
    f=open(myargs[0])
except :
    print >>stderr,"ERROR [gmt2vcs_continents.py]!!"
    print >>stderr,"File %s not found."%myargs[0]
    sys.exit(1)
    
# Open VCS output file
try:
    fout=open(OutFileName,'w')
except :
    print >>stderr,"ERROR [gmt2vcs_continents.py]!!"
    print >>stderr,"Can't open %s for writting."%OutFileName
    sys.exit(1)
    
y=[]
x=[]

# Nb of points per line in VCS file (for lisibility)
NbPtLigne=4
# Maximum points for one polyline
NbMaxPts=100

for l in f.xreadlines():
    # special character'>' for new polyline
    if l[0]=='>':
        print_poly(fout,x,y)
        x=[]
        y=[]
    elif l[0] == '#': # Comments
        pass
    else:
        # In VCS polylines must not have more than 200 points
        if len(x) >= NbMaxPts: 
            print_poly(fout,x,y)
            # Last point of the last polyline is the first of next one
            x=[x[NbMaxPts-1]]
            y=[y[NbMaxPts-1]]
        sp=l.split()
        
        lon=string.atof(sp[0])
        lat=string.atof(sp[1])
        if lon>180:lon=lon-360
        x.append(lon)
        y.append(lat)
# Last polyline
print_poly(fout,x,y)
# Closing file characters
print >> fout," -99    -99 "
fout.close()