from __future__ import (absolute_import, division, print_function) import numpy as np #from .extension import computedbz,computetk from .extension import _dbz, _tk from .constants import Constants from .util import extract_vars, to_np from .metadecorators import copy_and_set_metadata @copy_and_set_metadata(copy_varname="T", name="dbz", description="radar reflectivity", units="dBZ") def get_dbz(wrfin, timeidx=0, method="cat", squeeze=True, cache=None, meta=True, _key=None, use_varint=False, use_liqskin=False): """Return the simulated radar reflectivity. This functions extracts the necessary variables from the NetCDF file object in order to perform the calculation. Args: wrfin (:class:`netCDF4.Dataset`, :class:`Nio.NioFile`, or an \ iterable): WRF-ARW NetCDF data as a :class:`netCDF4.Dataset`, :class:`Nio.NioFile` or an iterable sequence of the aforementioned types. timeidx (:obj:`int` or :data:`wrf.ALL_TIMES`, optional): The desired time index. This value can be a positive integer, negative integer, or :data:`wrf.ALL_TIMES` (an alias for None) to return all times in the file or sequence. The default is 0. method (:obj:`str`, optional): The aggregation method to use for sequences. Must be either 'cat' or 'join'. 'cat' combines the data along the Time dimension. 'join' creates a new dimension for the file index. The default is 'cat'. squeeze (:obj:`bool`, optional): Set to False to prevent dimensions with a size of 1 from being automatically removed from the shape of the output. Default is True. cache (:obj:`dict`, optional): A dictionary of (varname, ndarray) that can be used to supply pre-extracted NetCDF variables to the computational routines. It is primarily used for internal purposes, but can also be used to improve performance by eliminating the need to repeatedly extract the same variables used in multiple diagnostics calculations, particularly when using large sequences of files. Default is None. meta (:obj:`bool`, optional): Set to False to disable metadata and return :class:`numpy.ndarray` instead of :class:`xarray.DataArray`. Default is True. _key (:obj:`int`, optional): A caching key. This is used for internal purposes only. Default is None. use_varint (:obj:`bool`, optional): When set to False, the intercept parameters are assumed constant (as in MM5's Reisner-2 bulk microphysical scheme). When set to True, the variable intercept parameters are used as in the more recent version of Reisner-2 (based on Thompson, Rasmussen, and Manning, 2004, Monthly weather Review, Vol. 132, No. 2, pp. 519-542.). use_liqskin (:obj:`bool`, optional): When set to True, frozen particles that are at a temperature above freezing are assumed to scatter as a liquid particle. Set to False to disable. Returns: :class:`xarray.DataArray` or :class:`numpy.ndarray`: The simulated radar reflectivity. If xarray is enabled and the *meta* parameter is True, then the result will be a :class:`xarray.DataArray` object. Otherwise, the result will be a :class:`numpy.ndarray` object with no metadata. """ varnames = ("T", "P", "PB", "QVAPOR", "QRAIN") ncvars = extract_vars(wrfin, timeidx, varnames, method, squeeze, cache, meta=False, _key=_key) t = ncvars["T"] p = ncvars["P"] pb = ncvars["PB"] qv = ncvars["QVAPOR"] qr = ncvars["QRAIN"] try: snowvars = extract_vars(wrfin, timeidx, "QSNOW", method, squeeze, cache, meta=False, _key=_key) except KeyError: qs = np.zeros(qv.shape, qv.dtype) else: qs = snowvars["QSNOW"] try: graupvars = extract_vars(wrfin, timeidx, "QGRAUP", method, squeeze, cache, meta=False, _key=_key) except KeyError: qg = np.zeros(qv.shape, qv.dtype) else: qg = graupvars["QGRAUP"] full_t = t + Constants.T_BASE full_p = p + pb tk = _tk(full_p, full_t) # If qsnow is not all 0, set sn0 to 1 sn0 = 1 if qs.any() else 0 ivarint = 1 if use_varint else 0 iliqskin = 1 if use_liqskin else 0 return _dbz(full_p, tk, qv, qr, qs, qg, sn0, ivarint, iliqskin) @copy_and_set_metadata(copy_varname="T", name="max_dbz", remove_dims=("bottom_top",), description="maximum radar reflectivity", units="dBZ", MemoryOrder="XY") def get_max_dbz(wrfin, timeidx=0, method="cat", squeeze=True, cache=None, meta=True, _key=None, use_varint=False, use_liqskin=False): """Return the maximum simulated radar reflectivity. This function returns the maximum reflectivity found in the column for each grid point. This functions extracts the necessary variables from the NetCDF file object in order to perform the calculation. Args: wrfin (:class:`netCDF4.Dataset`, :class:`Nio.NioFile`, or an \ iterable): WRF-ARW NetCDF data as a :class:`netCDF4.Dataset`, :class:`Nio.NioFile` or an iterable sequence of the aforementioned types. timeidx (:obj:`int` or :data:`wrf.ALL_TIMES`, optional): The desired time index. This value can be a positive integer, negative integer, or :data:`wrf.ALL_TIMES` (an alias for None) to return all times in the file or sequence. The default is 0. method (:obj:`str`, optional): The aggregation method to use for sequences. Must be either 'cat' or 'join'. 'cat' combines the data along the Time dimension. 'join' creates a new dimension for the file index. The default is 'cat'. squeeze (:obj:`bool`, optional): Set to False to prevent dimensions with a size of 1 from being automatically removed from the shape of the output. Default is True. cache (:obj:`dict`, optional): A dictionary of (varname, ndarray) that can be used to supply pre-extracted NetCDF variables to the computational routines. It is primarily used for internal purposes, but can also be used to improve performance by eliminating the need to repeatedly extract the same variables used in multiple diagnostics calculations, particularly when using large sequences of files. Default is None. meta (:obj:`bool`, optional): Set to False to disable metadata and return :class:`numpy.ndarray` instead of :class:`xarray.DataArray`. Default is True. _key (:obj:`int`, optional): A caching key. This is used for internal purposes only. Default is None. use_varint (:obj:`bool`, optional): When set to False, the intercept parameters are assumed constant (as in MM5's Reisner-2 bulk microphysical scheme). When set to True, the variable intercept parameters are used as in the more recent version of Reisner-2 (based on Thompson, Rasmussen, and Manning, 2004, Monthly weather Review, Vol. 132, No. 2, pp. 519-542.). use_liqskin (:obj:`bool`, optional): When set to True, frozen particles that are at a temperature above freezing are assumed to scatter as a liquid particle. Set to False to disable. Returns: :class:`xarray.DataArray` or :class:`numpy.ndarray`: The maximum simulated radar reflectivity. If xarray is enabled and the *meta* parameter is True, then the result will be a :class:`xarray.DataArray` object. Otherwise, the result will be a :class:`numpy.ndarray` object with no metadata. """ return np.amax(to_np(get_dbz(wrfin, timeidx, method, squeeze, cache, meta, _key, use_varint, use_liqskin)), axis=-3)