add_corners

#!/usr/bin/env python

import osr
import netCDF4 as nc
import numpy as np
import sys
import getopt
from argparse import ArgumentParser


def add_corners (filename, opts={}):
    infile=nc.Dataset(filename,"r")
    #infile=nc.Dataset("test.nc","r")
    outfile=nc.Dataset("ll_%s"%(filename), "w", format='NETCDF3_64BIT')

    x=infile.variables["lon"][:]
    y=infile.variables["lat"][:]

    xx = np.expand_dims(x,axis=0).repeat(len(y),axis=0)
    yy = np.expand_dims(y,axis=0).repeat(len(x),axis=0).transpose()
    fdx = outfile.createDimension("x", len(x))
    fdy = outfile.createDimension("y", len(y))
    fdy = outfile.createDimension("grid_corners", 4)

    fvx = outfile.createVariable("x","f4",("x",))
    fvy = outfile.createVariable("y","f4",("y",))
    fvx[:] = x
    fvy[:] = y
    fvx.units = "degrees"
    fvy.units = "degrees"

    lon = outfile.createVariable("lon","f4",("y","x"), fill_value=-9.e9)
    lat = outfile.createVariable("lat","f4",("y","x"), fill_value=-9.e9)

    lon.units = "degrees"
    lon.long_name = "longitude"
    lon.standard_name = "longitude"
    lon.bounds = "grid_corner_lon"
    lon._CoordinateAxisType = "Lon"


    lat.units = "degrees"
    lat.long_name = "latitude"
    lat.standard_name = "latitude"
    lat.bounds = "grid_corner_lat"
    lat._CoordinateAxisType = "Lat"

    lon[:] = xx
    lat[:] = yy
    xoff=(x[1]-x[0])/2.
    yoff=(y[1]-y[0])/2.
    print xoff
    print yoff
    addx = [ xoff, xoff,-xoff,-xoff]
    addy = [-yoff, yoff, yoff,-yoff]

    grid_corner_lat = outfile.createVariable("grid_corner_lat","f4", ("y", "x", "grid_corners"), fill_value=-9.e9)
    grid_corner_lon = outfile.createVariable("grid_corner_lon","f4", ("y", "x", "grid_corners"), fill_value=-9.e9)

    grid_corner_lat.units = "degrees"
    grid_corner_lon.units = "degrees"

    for i in xrange(4):
        grid_corner_lon[:,:,i] = xx+addx[i]
        grid_corner_lat[:,:,i] = yy+addy[i]

    outfile.close()


    
def parse_args():
  parser = ArgumentParser()
  parser.description = "compare slopes of two variables from two files"
  parser.add_argument("FILES", nargs=1)
  parser.add_argument("-v", "--verbose", 
                    help='''Be verbose''', action="store_true")
  parser.add_argument("-u", "--utm", 
                        help='''File is using utm coordinates''', default = None, type = int) 
  # parser.add_argument("-s", "--state", 
  #                      help='''file with reference values''', required = True) 
  # parser.add_argument("-b", "--var_b", 
  #                    help='''variable b''', default="data")
  options = parser.parse_args()
  return options


def main():
  options = parse_args()
  if options.verbose:
    print (dir(options))
    print options.FILES
    fu.debug=True


  
  add_corners(options.FILES[0], vars(options))
    


if __name__ == "__main__":
    main()