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Flipping zeroes and ones in one-dimensional NumPy array

I have a one-dimensional NumPy array that consists of zeroes and ones like so:

array([0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1])

I'd like a quick way to just "flip" the values such that zeroes become ones, and ones become zeroes, resulting in a NumPy array like this:

array([1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0])

Is there an easy one-liner for this? I looked at the fliplr() function, but this seems to require NumPy arrays of dimensions two or greater. I'm sure there's a fairly simple answer, but any help would be appreciated.

like image 816
kylerthecreator Avatar asked Nov 12 '14 15:11

kylerthecreator


3 Answers

There must be something in your Q that i do not understand...

Anyway

In [2]: from numpy import array

In [3]: a = array((1,0,0,1,1,0,0))

In [4]: b = 1-a

In [5]: print a ; print b
[1 0 0 1 1 0 0]
[0 1 1 0 0 1 1]

In [6]: 
like image 64
gboffi Avatar answered Oct 01 '22 05:10

gboffi


A sign that you should probably be using a boolean datatype

a = np.array([0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1], dtype=np.bool)
# or
b = ~a
b = np.logical_not(a)
like image 34
YXD Avatar answered Oct 01 '22 03:10

YXD


another superfluous option:

numpy.logical_not(a).astype(int)
like image 27
John Greenall Avatar answered Oct 01 '22 03:10

John Greenall