def attach(self, filename, Vars=None, Cache=False):
"""
Attach variables from gridded meteorological files, interpolating
from the gridded values to the (lat,lon) of the fire. If the variables
are 3D, the whole curtain is included. If *Vars* is not specified,
all non-coordinate variables on file are included.
When *Cache* is true, the variables are saved locally to directory
"__cache__". When the input file name is "__cache__", the variables are read
from cache.
"""
from grads import GrADS
# Expects GrADS v2
# ----------------
ga = GrADS(Bin='grads', Window=False, Echo=False)
# Open the file
# -------------
fh = ga.open(filename)
ga('set lon -180 180') # good for interpolation
# Either all varibles on file or user subset
# ------------------------------------------
if Vars == None:
vinfo = fh.var_info
else:
vinfo = []
for v, k, l in fh.var_info:
if v in Vars:
vinfo.append((v, k, l))
if len(vinfo) == 0:
print "IndexError: requested variables - ", Vars
raise IndexError, "cannot find any matchig variable in file %f"\
%filename
# For each observation, find the correspondng time on file
# --------------------------------------------------------
utimes = unique(self.tga) # unique obs times in grads format
self.tgaf = self.tga.copy() # will hold times on file for each ob
for tga in utimes:
ga('set time %s' % tga, Quiet=True)
qh = ga('query time', Quiet=True)
self.tgaf[self.tga == tga] = ga.rword(1, 3)
# Loop over each desired variable and interpolate it to
# fire location
# -----------------------------------------------------
self.met = {}
n = self.lon.size
levs = 1000. * zeros(fh.nz)
for v, nlevs, l in vinfo:
if nlevs == 0:
nlevs = 1
y_f = zeros(n)
else:
y_f = zeros((n, nlevs))
for tgaf in unique(self.tgaf):
ga('set time %s' % tgaf, Quiet=True)
ga('set z %d %d' % (1, nlevs), Quiet=True)
m = (self.tgaf == tgaf) # gather obs for this time
lon_, lat_ = (self.lon[m], self.lat[m])
print "- Interpolating %5d %s obs at %s" % (lon_.size, v, tgaf)
y_f[m], levs = ga.interp(v, lon_, lat_) # interp & scatter
self.met[v] = y_f
self.met['levs'] = levs # record vertical levels
class TestGrb2File(unittest.TestCase):
def tearDown(self):
del self.ga
def _GenericSetUp(self, bin):
global GrADSTestFiles
global GrADSBinaryFiles
self.ga = GrADS(Bin=GrADSBinaryFiles[bin], Echo=False, Window=False)
self.fh = self.ga.open(GrADSTestFiles['grb2'])
def test_01_Open(self):
"""
Check whether file was opened correctly.
"""
type = 'Gridded'
vars = [
'apcpsfc', 'hgtprs', 'prmslmsl', 'rhprs', 'tmpprs', 'ugrdprs',
'vgrdprs'
]
var_levs = [0, 3, 0, 3, 3, 3, 3]
nx, ny, nz, nt = (144, 73, 3, 4) # no E size yet
fh = self.fh
self.assertEqual(type, fh.type)
self.assertEqual(nx, fh.nx)
self.assertEqual(ny, fh.ny)
self.assertEqual(nz, fh.nz)
self.assertEqual(nt, fh.nt)
vars2 = fh.vars[:]
var_levs2 = fh.var_levs[:]
self.assertEqual(vars.sort(), vars2.sort())
self.assertEqual(var_levs.sort(), var_levs2.sort())
def test_03_Display(self):
"""
Displays several variables and checks contour intervals
"""
self._CheckCint('apcpsfc', 0, 140, 10, z=1, t=2)
self._CheckCint('0.01*prmslmsl', 950, 1050, 10, z=1, t=1)
self._CheckCint('hgtprs', 900, 1600, 100, z=1, t=1)
self._CheckCint('rhprs', 0, 100, 10, z=1, t=1)
self._CheckCint('tmpprs', 235, 300, 5, z=1, t=1)
self._CheckCint('ugrdprs', -30, 30, 10, z=1, t=1)
self._CheckCint('vgrdprs', -25, 35, 5, z=1, t=1)
self._CheckCint('apcpsfc', 0, 80, 10, z=1, t=4)
self._CheckCint('0.01*prmslmsl', 950, 1040, 10, z=1, t=4)
self._CheckCint('hgtprs', 900, 1600, 100, z=1, t=4)
self._CheckCint('rhprs', 0, 100, 10, z=1, t=4)
self._CheckCint('tmpprs', 240, 300, 5, z=1, t=4)
self._CheckCint('ugrdprs', -25, 30, 5, z=1, t=4)
self._CheckCint('vgrdprs', -25, 30, 5, z=1, t=4)
self._CheckCint('hgtprs', 10800, 12400, 200, z=3, t=4)
self._CheckCint('rhprs', 0, 100, 10, z=3, t=4)
self._CheckCint('tmpprs', 200, 235, 5, z=3, t=4)
self._CheckCint('ugrdprs', -40, 100, 10, z=3, t=4)
self._CheckCint('vgrdprs', -50, 50, 10, z=3, t=4)
def _CheckCint(self, name, cmin, cmax, cint, z=1, t=1):
"""
Check contour intervals during display.
"""
self.ga('clear')
self.ga('display %s(z=%d,t=%d)' % (name, z, t))
self.assertEqual(cmin, int(self.ga.rword(1, 2)))
self.assertEqual(cmax, int(self.ga.rword(1, 4)))
self.assertEqual(cint, int(self.ga.rword(1, 6)))
def _GenericSetUp(self, bin):
global GrADSTestFiles
global GrADSBinaryFiles
self.ga = GrADS(Bin=GrADSBinaryFiles[bin], Echo=False, Window=False)
self.fh = self.ga.open(GrADSTestFiles['grb2'])
