Source code for landlab.grid.decorators

"""This module defines decorators used with ModelGrid objects.

Grid decorators
+++++++++++++++

.. autosummary::

    ~override_array_setitem_and_reset
    ~return_id_array
    ~return_readonly_id_array
"""

from functools import wraps

import numpy as np

from ..core.utils import as_id_array


[docs] class override_array_setitem_and_reset: """Decorator that calls a grid method after setting array values. This decorator wraps `ModelGrid` methods that return a numpy array so that it returns a wrapped array that overrides the numpy array `__setitem__`, `__setslice__`, and `itemset` methods. The wrapped methods set values in the array but then also call a grid method that resets some state variables of the grid. Parameters ---------- reset : str The name of the grid method to call after setting values. The corresponding method must take no arguments. """
[docs] def __init__(self, reset): """Initialize the decorator with an argument. Parameters ---------- reset : str The name of the grid method to call after setting values. The corresponding method must take no arguments. """ self._reset = reset
[docs] def __call__(self, func): """Get a wrapped version of the method. Parameters ---------- func : function The grid method to wrap. Returns ------- function The wrapped function. """ reset = self._reset def _wrapped(grid): """Embed a grid into a numpy array and override set methods.""" class array(np.ndarray): """Override numpy setters and reset grid topology.""" def __new__(cls, arr): """Instantiate the class with a view of the base array.""" obj = np.asarray(arr).view(cls) obj.grid = grid return obj def __array_finalize__(self, obj): if obj is None: return def __setitem__(self, ind, value): """Set value of array, then call reset function.""" np.ndarray.__setitem__(self, ind, value) getattr(self.grid, reset)() def __setslice__(self, start, stop, value): """Set values of array, then call reset function.""" np.ndarray.__setslice__(self, start, stop, value) getattr(self.grid, reset)() return array(func(grid)) _wrapped.__name__ = func.__name__ _wrapped.__doc__ = func.__doc__ return _wrapped
[docs] def return_id_array(func): """Decorate a function to return an array of ids. Parameters ---------- func : function A function that returns a numpy array. Returns ------- func A wrapped function that returns an id array. """ @wraps(func) def _wrapped(self, *args, **kwds): """Create a function that returns an id array.""" return as_id_array(func(self, *args, **kwds)) return _wrapped
[docs] def return_readonly_id_array(func): """Decorate a function to return a read-only array of ids. Parameters ---------- func : function A function that returns a numpy array. Returns ------- func A wrapped function that returns an id array. """ @wraps(func) def _wrapped(self, *args, **kwds): """Create a function that returns an id array.""" id_array = as_id_array(func(self, *args, **kwds)) try: immutable_array = id_array.view() immutable_array.flags.writeable = False except ValueError: return id_array else: return immutable_array return _wrapped