If you are an R user, the following operations are as common as breathing. With this, the elements excluding specific subscripts can be extracted.
vec <- 1:10
ind_rm <- c(5, 7)
# ind_Extracting elements by specifying an index other than rm
print(vec[-ind_rm])
[1] 1 2 3 4 6 8 9 10
Unexpectedly, I can't think of a smart way to do it with numpy. I think everyone is in trouble. I'm sad if I'm the only one.
After all, the idea of something other than a specific element like R seems to be wrong in the first place, so let's think about how to make an array or list that includes the subscripts of the elements to be left obediently.
If I do it obediently, I feel like this, but I can't wipe out the feeling that something ʻin` or something is obviously uselessly calculated.
import numpy as np
vec = np.arange(10)
ind_rm = [5, 7]
# [0, 1, 2, 3, 4, 6, 8, 9]Want to make!
ind = [i for i in range(10) if i not in ind_rm]
print vec[ind]
Check with Stack overflow I was a little impressed with the following method.
import numpy as np
vec = np.arange(10)
ind_rm = [5, 7]
# [True, True, True, True, False, True, False, True, True, True]Policy to make
ind = np.ones(10, dtype=bool)
ind[ind_rm] = False
print vec[ind]
It doesn't save the number of lines, but it seems to be a little faster because there is no useless calculation.
I first learned that np.ones has such a usage.
Looking for a better way.
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