Source code for satpy.readers.xmlformat

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Copyright (c) 2012 Satpy developers
# This file is part of satpy.
# satpy is free software: you can redistribute it and/or modify it under the
# terms of the GNU General Public License as published by the Free Software
# Foundation, either version 3 of the License, or (at your option) any later
# version.
# satpy is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
# You should have received a copy of the GNU General Public License along with
# satpy.  If not, see <>.
"""Reads a format from an xml file to create dtypes and scaling factor arrays."""

from __future__ import annotations

from xml.etree.ElementTree import ElementTree

import numpy as np

VARIABLES: dict[str, str] = {}

TYPEC = {"boolean": ">i1",
         "integer2": ">i2",
         "integer4": ">i4",
         "uinteger2": ">u2",
         "uinteger4": ">u4", }

[docs]def process_delimiter(elt, ascii=False): """Process a 'delimiter' tag.""" del elt, ascii
[docs]def process_field(elt, ascii=False): """Process a 'field' tag.""" # NOTE: if there is a variable defined in this field and it is different # from the default, we could change the value and restart. scale = np.uint8(1) if elt.get("type") == "bitfield" and not ascii: current_type = ">u" + str(int(elt.get("length")) // 8) scale = np.dtype(current_type).type(1) elif (elt.get("length") is not None): if ascii: add = 33 else: add = 0 current_type = "S" + str(int(elt.get("length")) + add) else: current_type = TYPEC[elt.get("type")] try: scale = (10 / float(elt.get("scaling-factor", "10").replace("^", "e"))) except ValueError: scale = (10 / np.array( elt.get("scaling-factor").replace("^", "e").split(","), dtype=np.float64)) return ((elt.get("name"), current_type, scale))
[docs]def process_array(elt, ascii=False): """Process an 'array' tag.""" del ascii chld = list(elt) if len(chld) > 1: raise ValueError() chld = chld[0] try: name, current_type, scale = CASES[chld.tag](chld) size = None except ValueError: name, current_type, size, scale = CASES[chld.tag](chld) del name myname = elt.get("name") or elt.get("label") if elt.get("length").startswith("$"): length = int(VARIABLES[elt.get("length")[1:]]) else: length = int(elt.get("length")) if size is not None: return (myname, current_type, (length, ) + size, scale) else: return (myname, current_type, (length, ), scale)
CASES = {"delimiter": process_delimiter, "field": process_field, "array": process_array, }
[docs]def to_dtype(val): """Parse *val* to return a dtype.""" return np.dtype([i[:-1] for i in val])
[docs]def to_scaled_dtype(val): """Parse *val* to return a dtype.""" res = [] for i in val: if i[1].startswith("S"): res.append((i[0], i[1]) + i[2:-1]) else: try: res.append((i[0], i[-1].dtype) + i[2:-1]) except AttributeError: res.append((i[0], type(i[-1])) + i[2:-1]) return np.dtype(res)
[docs]def to_scales(val): """Parse *val* to return an array of scale factors.""" res = [] for i in val: if len(i) == 3: res.append((i[0], type(i[2]))) else: try: res.append((i[0], i[3].dtype, i[2])) except AttributeError: res.append((i[0], type(i[3]), i[2])) dtype = np.dtype(res) scales = np.zeros((1, ), dtype=dtype) for i in val: try: scales[i[0]] = i[-1] except ValueError: scales[i[0]] = np.repeat(np.array(i[-1]), i[2][1]).reshape(i[2]) return scales
[docs]def parse_format(xml_file): """Parse the xml file to create types, scaling factor types, and scales.""" tree = ElementTree() tree.parse(xml_file) for param in tree.find("parameters"): VARIABLES[param.get("name")] = param.get("value") types_scales = {} for prod in tree.find("product"): ascii = (prod.tag in ["mphr", "sphr"]) res = [] for i in prod: lres = CASES[i.tag](i, ascii) if lres is not None: res.append(lres) types_scales[(prod.tag, int(prod.get("subclass")))] = res types = {} stypes = {} scales = {} for key, val in types_scales.items(): types[key] = to_dtype(val) stypes[key] = to_scaled_dtype(val) scales[key] = to_scales(val) return types, stypes, scales
def _apply_scales(array, scales, dtype): """Apply scales to the array.""" new_array = np.empty(array.shape, dtype) for i in array.dtype.names: try: new_array[i] = array[i] * scales[i] except TypeError: if np.all(scales[i] == 1): new_array[i] = array[i] else: raise return new_array
[docs]class XMLFormat(object): """XMLFormat object.""" def __init__(self, filename): """Init the format reader.""" self.types, self.stypes, self.scales = parse_format(filename) self.translator = {} for key, val in self.types.items(): self.translator[val] = (self.scales[key], self.stypes[key])
[docs] def dtype(self, key): """Get the dtype for the format object.""" return self.types[key]
[docs] def apply_scales(self, array): """Apply scales to *array*.""" return _apply_scales(array, *self.translator[array.dtype])
if __name__ == '__main__': pass