Commit 74233811 authored by pavan kumar.siligam's avatar pavan kumar.siligam

2d variables with cdo

parent 82580fe3
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# -*- coding: utf-8 -*-
from __future__ import print_function
import math
import collections
"""Geolocation (lat,lon) utility functions for calculating bounding box and
Inspiration from the following sources:
__author__ = "Pavan Siligam <>"
_geoboundingbox = collections.namedtuple('geoboundingbox', 'll ur')
class geoboundingbox(_geoboundingbox):
def __new__(cls, lowerleft, upperright):
FLIP = False
ll_lat, ll_lon = lowerleft
ur_lat, ur_lon = upperright
# check if it is indeed lowerleft and upperright corners
if sum([ll_lat > ur_lat, ll_lon > ur_lon]) == 1:
print('Recieved opposite corners... correcting corners')
lowerleft = ur_lat, ll_lon
upperright = ll_lat, ur_lon
if lowerleft[0] > upperright[0]:
FLIP = True
print('Flipping corners...')
lowerleft, upperright = upperright, lowerleft
if FLIP:
direction = 'NorthWest'
direction = 'SouthEast'
if FLIP:
direction = 'SouthWest'
direction = 'NorthEast'
ll = loc(*lowerleft)
ur = loc(*upperright)
box = super(geoboundingbox, cls).__new__(cls, ll, ur)
box.direction = direction
return box
def ul(self):
return loc(, self.ll.lon)
def lr(self):
return loc(, self.ur.lon)
def tics(self):
return (self.ul, self.ur,, self.ll)
_loc = collections.namedtuple('loc', 'lat lon')
class loc(_loc):
RADIUS = 6378.1 # radius of Earth in km
LON_BOUNDS = -180, 180
LAT_BOUNDS = -90, 90
def __new__(cls, lat, lon):
errors = []
lat_min, lat_max = cls.LAT_BOUNDS
if not (lat_min <= lat <= lat_max):
msg = "lat({}) outside valid bounds {!r}"
errors.append(msg.format(lat, cls.LAT_BOUNDS))
lon_min, lon_max = cls.LON_BOUNDS
if not (lon_min <= lon <= lon_max):
msg = "lon({}) outside valid bounds {!r}"
errors.append(msg.format(lon, cls.LON_BOUNDS))
if errors:
raise ValueError(", ".join(errors))
return super(loc, cls).__new__(cls, lat, lon)
def from_radians(cls, rlat, rlon):
lat = math.degrees(rlat)
lon = math.degrees(rlon)
return cls(lat, lon)
def rlat(self):
return math.radians(
def rlon(self):
return math.radians(self.lon)
def distance_to(self, other):
Computes the great circle distance between this Loc instance
and the other.
if not isinstance(other, self.__class__):
other = self.__class__(*other)
acos = math.acos
sin = math.sin
cos = math.cos
rlat = self.rlat
rlon = self.rlon
other_rlat = other.rlat
other_rlon = other.rlon
return self.RADIUS * acos(
sin(rlat) * sin(other_rlat) +
cos(rlat) * cos(other_rlat) * cos(rlon - other_rlon))
def bounding_box(self, distance):
"distance in KM"
asin = math.asin
sin = math.sin
cos = math.cos
radians = math.radians
degrees = math.degrees
rlat = self.rlat
rlon = self.rlon
lat_bound_min, lat_bound_max = map(radians, self.LAT_BOUNDS)
lon_bound_min, lon_bound_max = map(radians, self.LON_BOUNDS)
if distance < 0:
raise ValueError("distance must to positive")
rdist = 1.0 * distance / self.RADIUS
lat_min = rlat - rdist
lat_max = rlat + rdist
if (lat_min > lat_bound_min) and (lat_max < lat_bound_max):
dlon = asin(sin(rdist) / cos(rlat))
lon_min = rlon - dlon
if lon_min < lon_bound_min:
lon_min += 2 * math.pi
lon_max = rlon + dlon
if lon_max > lon_bound_max:
lon_max -= 2 * math.pi
lat_min = max(lat_min, lat_bound_min)
lat_max = min(lat_max, lat_bound_max)
lon_min = lon_bound_min
lon_max = lon_bound_max
lowerleft = tuple(map(degrees, (lat_min, lon_min)))
upperright = tuple(map(degrees, (lat_max, lon_max)))
return geoboundingbox(lowerleft, upperright)
if __name__ == "__main__":
# Test degree to radian conversion
loc1 = loc(26.062951, -80.238853)
loc2 = loc.from_radians(loc1.rlat, loc1.rlon)
assert (loc1.rlat == loc2.rlat and loc1.rlon == loc2.rlon and == and loc1.lon == loc2.lon)
# Test distance between two locations
loc1 = loc(26.062951, -80.238853)
loc2 = loc(26.060484, -80.207268)
assert loc1.distance_to(loc2) == loc2.distance_to(loc1)
# Test bounding box
loc1 = loc(26.062951, -80.238853)
distance = 1 # 1 kilometer
SW_loc, NE_loc = loc1.bounding_box(distance)
#!/usr/bin/env python
# -*- coding: utf-8 -*-
from __future__ import print_function
import os
import numpy as np
from geolocation import loc
from collections import OrderedDict, namedtuple
"""Generates description of the target grid for a given resolution and lat-lon
bounds. This description is one of the input parameters for the cdo operator
__author__ = "Pavan Siligam <>"
__contributors__ = ("Rieke Heinze <>",)
_bounds = namedtuple("Bounds", "lon_min lon_max lat_min lat_max")
griddes = OrderedDict()
griddes["gridtype"] = "lonlat"
griddes["gridsize"] = ""
griddes["xname"] = "lon"
griddes["xlongname"] = "longitude"
griddes["xunits"] = "degrees_east"
griddes["yname"] = "lat"
griddes["ylongname"] = "latitude"
griddes["yunits"] = "degrees_north"
griddes["xsize"] = ""
griddes["ysize"] = ""
griddes["xfirst"] = ""
griddes["xinc"] = ""
griddes["yfirst"] = ""
griddes["yinc"] = ""
_resolution_factor = 0.67
icon_grids = {"DOM03": 0.156,
"DOM02": 0.312,
"DOM01": 0.625}
def get_resolution(grid_name_or_resolution_in_km, icon_grids=icon_grids):
"""Resolution of the target grid.
:param grid_name_or_resolution_in_km: Only in case of named grid,
the resolution is computed by taking the product of native
resolution of the grid and the resolution factor. Otherwise
the value is returned as is.
def handle_grid_names(name):
possible_names = ("d{}", "d{:02d}", "dom{}",
"dom{:02d}", "domain{}", "domain{:02d}")
req_names = sorted(icon_grids.keys())
if name in req_names:
return name
for idx, rname in enumerate(req_names, 1):
_name = " ".join([n.format(idx) for n in possible_names])
if name in _name:
return rname
return name
resolution = float(grid_name_or_resolution_in_km)
except ValueError:
grid_name = handle_grid_names(grid_name_or_resolution_in_km)
resolution = icon_grids[grid_name] * _resolution_factor
return resolution
def get_bounds(bounds_or_filename):
# expecting a string with comma seperated values
bounds = _bounds(*map(float, bounds_or_filename.split(",")))
except AttributeError:
# could be a tuple or a list
bounds = _bounds(*map(float, bounds_or_filename))
except ValueError:
# could be a filename
bounds = bounds_from_file(bounds_or_filename)
except IOError:
return bounds
def bounds_from_file(filename):
import netCDF4
with netCDF4.Dataset(filename) as nc:
lats = np.rad2deg(nc.variables['clat'][:])
lons = np.rad2deg(nc.variables['clon'][:])
lats = nc.variables['lat'][:]
lons = nc.variables['lon'][:]
lat_min = lats.min()
lat_max = lats.max()
lon_min = lons.min()
lon_max = lons.max()
return _bounds(lon_min, lon_max, lat_min, lat_max)
def gridspec(bounds_or_filename, grid_name_or_resolution_in_km,
gs = griddes.copy()
resolution = get_resolution(grid_name_or_resolution_in_km)
bounds = get_bounds(bounds_or_filename)
lon_min = bounds.lon_min
lon_max = bounds.lon_max
lat_min = bounds.lat_min
lat_max = bounds.lat_max
ll = loc(lat_min, lon_min)
ur = loc(lat_max, lon_max)
dist = int(ll.distance_to(ur))
nparts = dist if dist > 0 else 11
points_lats = np.linspace(lat_min, lat_max, nparts)
points_lons = np.linspace(lon_min, lon_max, nparts)
points = zip(points_lats, points_lons)
inc_yx = [_increment(pnt, resolution) for pnt in points]
inc_x, inc_y = zip(*inc_yx)
xinc = round(np.average(inc_x), 4)
yinc = round(np.average(inc_y), 4)
gs['xfirst'] = round(lon_min, 4)
gs['yfirst'] = round(lat_min, 4)
gs['xinc'] = round(xinc, 4)
gs['yinc'] = round(yinc, 4)
gs['xsize'] = int(np.floor((lon_max - lon_min)/xinc))
gs['ysize'] = int(np.floor((lat_max - lat_min)/yinc))
gs['gridsize'] = gs['xsize'] * gs['ysize']
gs_text = ["{:<10} = {}".format(k, v) for k, v in gs.items()]
gs_text = "\n".join(gs_text)
if filehandle is None:
print(gs_text, file=filehandle)
return gs
def _increment(point, resolution, loc=loc):
p = loc(*point)
b = p.bounding_box(resolution)
x = p.lon - b.ll.lon
y = -
return x, y
def cli():
import argparse
class customFormatter(argparse.RawTextHelpFormatter):
def handle_grid_names(name):
possible_names = ("{:02d}", "d{}", "d{:02d}", "dom{}",
"dom{:02d}", "domain{}", "domain{:02d}")
req_names = "DOM01", "DOM02", "DOM03"
if name in req_names:
return name
for idx, rname in enumerate(req_names, 1):
_name = " ".join([n.format(idx) for n in possible_names])
if name in _name:
return rname
return name
doc_strings = {}
doc_strings['description'] = """
Generates description of the target grid for a given resolution and lat-lon
bounds. This description is one of the input parameters for the cdo operator
doc_strings['resolution'] = """
Resolution of the target grid in Kilometers.
doc_strings['domain'] = """
Domain to be used for calculating resolution. In this case, the resolution of
the target grid is most similar to the native resolution of the domain
selected. The triangle edge lengths in the ICON grid are 625m, 312m, 156m for
DOM01, DOM02, DOM03, respectively.
doc_strings['outfile'] = """
File to which output must be written. (default: stdout)
doc_strings['bounds'] = """
Comma separated corner tics of region of interest given as
'lon1,lon2,lat1,lat2'. These corner tics refer to the lower left and upper
right corners.
doc_strings['ncfile'] = """
Grid file from which the corner tics are to be read. Use this option if
the full extent of grid is considered to be the region of interest.
doc_strings['epilog'] = """
options '--resolution' and '--domain' are mutually exclusive.
Provide either one of these.
In case of option '--domain', the resolution obtained from the specified domain
(DOM01,DOM02,DOM03) is obtained by multiplying the native triangle edge length
with a factor of 0.67 which is equivalent to defining the resolution as square
root of the area of the triangle.
For details about this factor, please refer to:
"A. Dipankar, B. Stevens, R. Heinze, C. Moseley, G. Zängl, M. Giorgetta, and
S. Brdar (2015),Large eddy simulation using the general circulation model ICON,
J. Adv. Model. Earth Syst., 7, 963–986, doi:10.1002/2015MS000431."
options '--bounds' and '--ncfile' are also mutually exclusive.
Provide either one of these.
1. To generate a grid description for a 10x10 grid around joyce for DOM03
python {0} --outfile joyce_10x10_griddes --domain DOM03 --bounds 6.2715,6.5564,50.8191,50.9988
2. To generate a grid description for entire domain for DOM03
python {0} -d DOM03 -f /work/bm0834/k203095/OUTPUT/GRIDS/
3. To generate a grid description for a custom resolution of 400m
python {0} --resolution=0.4 --bounds 6.2715,6.5564,50.8191,50.9988
TIP: Leave no whitespaces between the option and its value.
python {0} -ogriddes -dDOM02 -b6.27,6.55,50.81,50.99
python {0} --outfile=griddes --domain=DOM02 --bounds=6.27,6.55,50.81,50.99
parser = argparse.ArgumentParser(description=doc_strings['description'],
parser.add_argument('-o', '--outfile',
type=argparse.FileType('wb', 0), default='-')
res_group = parser.add_mutually_exclusive_group(required=True)
res_group.add_argument('-r', '--resolution',
res_group.add_argument('-d', '--domain',
choices=("DOM01", "DOM02", "DOM03"),
tics_group = parser.add_mutually_exclusive_group(required=True)
tics_group.add_argument('-b', '--bounds',
tics_group.add_argument('-f', '--ncfile',
args = parser.parse_args()
grid_name_or_resolution_in_km = args.resolution or args.domain
bounds_or_filename = args.bounds or args.ncfile
gridspec(bounds_or_filename, grid_name_or_resolution_in_km, args.outfile)
if __name__ == '__main__':
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