def compute_rtma_bounds(bbox):
"""
Compute bounds from RTMA data even when RTMA data is not available from terrain static data
:param bbox: the bounding box of the data
:return: a tuple containing bound coordinates (min_lon,max_lon,min_lat,max_lat)
"""
lats, lons = GribFile('static/ds.terrainh.bin')[1].latlons()
i1, i2, j1, j2 = find_region_indices(lats, lons, bbox[0], bbox[2], bbox[1],
bbox[3])
lats, lons = lats[i1:i2, j1:j2], lons[i1:i2, j1:j2]
return (lons.min(), lons.max(), lats.min(), lats.max())
def load_rtma_data(rtma_data, bbox):
"""
Load relevant RTMA fields and return them
:param rtma_data: a dictionary mapping variable names to local paths
:param bbox: the bounding box of the data
:return: a tuple containing t2, rh, lats, lons
"""
gf = GribFile(rtma_data['temp'])[1]
lats, lons = gf.latlons()
# bbox format: minlat, minlon, maxlat, maxlon
i1, i2, j1, j2 = find_region_indices(lats, lons, bbox[0], bbox[2], bbox[1],
bbox[3])
t2 = np.ma.array(gf.values())[i1:i2, j1:j2] # temperature at 2m in K
td = np.ma.array(GribFile(
rtma_data['td'])[1].values())[i1:i2, j1:j2] # dew point in K
precipa = np.ma.array(GribFile(
rtma_data['precipa'])[1].values())[i1:i2, j1:j2] # precipitation
hgt = np.ma.array(GribFile('static/ds.terrainh.bin')[1].values())[i1:i2,
j1:j2]
logging.info('t2 min %s max %s' % (np.min(t2), np.max(t2)))
logging.info('td min %s max %s' % (np.min(td), np.max(td)))
logging.info('precipa min %s max %s' % (np.min(precipa), np.max(precipa)))
logging.info('hgt min %s max %s' % (np.min(hgt), np.max(hgt)))
# compute relative humidity
rh = 100 * np.exp(17.625 * 243.04 * (td - t2) / (243.04 + t2 - 273.15) /
(243.0 + td - 273.15))
return td, t2, rh, precipa, hgt, lats[i1:i2, j1:j2], lons[i1:i2, j1:j2]
def load_rtma_data(rtma_data, bbox):
"""
Load relevant RTMA fields and return them
:param rtma_data: a dictionary mapping variable names to local paths
:param bbox: the bounding box of the data
:return: a tuple containing t2, rh, lats, lons
"""
gf = GribFile(rtma_data['temp'])[1]
lats, lons = gf.latlons()
# bbox format: minlat, minlon, maxlat, maxlon
i1, i2, j1, j2 = find_region_indices(lats, lons, bbox[0], bbox[2], bbox[1], bbox[3])
t2 = gf.values()[i1:i2,j1:j2] # temperature at 2m in K
td = GribFile(rtma_data['td'])[1].values()[i1:i2,j1:j2] # dew point in K
rain = GribFile(rtma_data['precipa'])[1].values()[i1:i2,j1:j2] # precipitation
hgt = GribFile('static/ds.terrainh.bin')[1].values()[i1:i2,j1:j2]
# compute relative humidity
rh = 100*np.exp(17.625*243.04*(td - t2) / (243.04 + t2 - 273.15) / (243.0 + td - 273.15))
return t2, rh, rain, hgt, lats[i1:i2,j1:j2], lons[i1:i2,j1:j2]