如何查找值大于numpy中某个阈值的数组的索引？

Question

In python (3.5.2) I have an increasing array of values, and I want to find the index at which the values become larger than some threshold.

I tried the following code

f = [0.0, 9.7, 19.5, 29.2, 39.0, 48.8, 58.5, 68.3, 78.1, 87.8, 97.6, 107.4, 117.1, 126.9]
index = min(np.argwhere(f>100))

which yields an error

TypeError: unorderable types: list() > int()

however, the expected outcome is index=11 , as f[11] is the first element of the array f to be larger than 100.

How to fix this code? Is there a better way?

Answer 1

This will do it:

np.argwhere(np.array(f)>100).min()

Or:

np.argmax(np.array(f)>100)

Take note that argmax stops at first index that evaluates condition to True .