Here I have a N*4 matrix  F with data from 0 to 1,I want to get a (N,) index tensor which requires
for every row in F , return the first value’s index which value >=R
if there is no such value in this row , return the max value’s index
Here’s an example(R=0.7)
[
[0.5 0.8 0.9 0.3],
[0.5 0.8 0.7 0.3],
[0.6 0.4 0.3 0.4],
]
will get
[1,1,0]
Thank you very much!