hub/venv/lib/python3.7/site-packages/pyny3d/utils.py

83 lines
2.3 KiB
Python

# -*- coding: utf-8 -*-
import numpy as np
'''
General purpose functions for clean up the code in critical areas.
'''
def sort_numpy(array, col=0, order_back=False):
"""
Sorts the columns for an entire ``ndarrray`` according to sorting
one of them.
:param array: Array to sort.
:type array: ndarray
:param col: Master column to sort.
:type col: int
:param order_back: If True, also returns the index to undo the
new order.
:type order_back: bool
:returns: sorted_array or [sorted_array, order_back]
:rtype: ndarray, list
"""
x = array[:,col]
sorted_index = np.argsort(x, kind = 'quicksort')
sorted_array = array[sorted_index]
if not order_back:
return sorted_array
else:
n_points = sorted_index.shape[0]
order_back = np.empty(n_points, dtype=int)
order_back[sorted_index] = np.arange(n_points)
return [sorted_array, order_back]
def arange_col(n, dtype=int):
"""
Returns ``np.arange`` in a column form.
:param n: Length of the array.
:type n: int
:param dtype: Type of the array.
:type dtype: type
:returns: ``np.arange`` in a column form.
:rtype: ndarray
"""
return np.reshape(np.arange(n, dtype = dtype), (n, 1))
def bool2index(bool_):
"""
Returns a numpy array with the indices where bool\_ is True.
:param bool_: bool array to extract Trues positions.
:type bool_: ndarray (type=bool)
:returns: Array with the indices where bool\_ is True.
:rtype: ndarray
.. seealso:: :func:`index2bool`
"""
return np.arange(bool_.shape[0])[bool_]
def index2bool(index, length=None):
"""
Returns a numpy boolean array with Trues in the input index
positions.
:param index: index array with the Trues positions.
:type index: ndarray (type=int)
:param length: Length of the returned array.
:type length: int or None
:returns: array with Trues in the input index positions.
:rtype: ndarray
.. seealso:: :func:`bool2index`
"""
if index.shape[0] == 0 and length is None:
return np.arange(0, dtype = bool)
if length is None: length = index.max()+1
sol = np.zeros(length, dtype=bool)
sol[index] = True
return sol