Binary Image Dataframe to Euclidean coordinates

Question

I am looking to take a dataframe of an image that is binary boolean of False/True's and transform it into an array of coordinates where the data frame is true.

For example, if index[4] and column[8] is true, it would add 4,8 to the array.

Answer 1

IIUC you can do it this way:

In [70]: df
Out[70]:
       a      b      c
0   True  False   True
1   True   True  False
2  False   True   True
3  False   True   True
4   True  False  False
5  False   True  False
6   True  False  False
7  False   True  False
8  False  False   True
9   True  False   True

In [71]: np.dstack(np.nonzero(df.values))[0]
Out[71]:
array([[0, 0],
       [0, 2],
       [1, 0],
       [1, 1],
       [2, 1],
       [2, 2],
       [3, 1],
       [3, 2],
       [4, 0],
       [5, 1],
       [6, 0],
       [7, 1],
       [8, 2],
       [9, 0],
       [9, 2]], dtype=int64)

or:

In [76]: np.stack(np.nonzero(df.values)).T
Out[76]:
array([[0, 0],
       [0, 2],
       [1, 0],
       [1, 1],
       [2, 1],
       [2, 2],
       [3, 1],
       [3, 2],
       [4, 0],
       [5, 1],
       [6, 0],
       [7, 1],
       [8, 2],
       [9, 0],
       [9, 2]], dtype=int64)

Setup:

df = pd.DataFrame(np.random.choice([True, False], (10, 3)), columns=list('abc'))