Numpy

Question

使用 np.instersect1d 后，我检索了我想要检索的索引。我想将这些索引变成一个遮罩，这样我就可以将它与另一个遮罩结合起来。

我要的是：

>>> times_1.shape
... (160,)

>>> _, time_indices, _ = np.intersect1d(times_1, times_2, return_indices=True)

>>> time_indices.shape
... (145,)

    # Some way to turn return mask from original shape and indices
>>> time_mask = get_mask_from_shape(time_1.shape, time_indices)

>>> time_mask.shape
... (160,)

实现功能 get_mask_from_shape 的最简单方法是什么？

Answer 1

如果我的想法正确，我会应用这个模式我一直在寻找 :

intersection = np.intersect1d(times_1, times_2)
intersection = np.sort(intersection)
locations = np.searchsorted(intersection, times_1)
locations[locations==len(intersection)] = 0
time_mask = intersection[locations]==times_1

根据 numpy documentation.

，

searchsorted 方法查找应将 times_1 的元素插入到 intersection 中以维持顺序的索引

Answer 2

我找到的解决方案是：

time_mask = np.zeros(times_1.shape, dtype=bool)
time_mask[time_indices] = True

Numpy - 从形状和索引中获取掩码

Numpy - get mask from shape and indices

python

mask

python-3.x