I have a potentially long array of one's and zero's that looks like this:
a = [0,0,1,0,1,0,.....]
I want to translate each consecutive pair of values to an integer between 0 & 3 as shown below:
I'm looking for a nice clean efficient way to create the array b (example output below) using the mapping above:
b = [0, 3, 3,...]
Is a dict a good idea? I can't figure out how to do it though.
Try:
x = np.reshape(a, (-1,2))
b = x[:,0]*2 + (x[:,0] ^ x[:,1])
If you want to use a dict with an explicit mapping between corresponding decimal numbers, you could try this:
# Convert to a (-1,2) matrix and decimal numbers first
a = np.reshape(a, (-1,2))
a = np.sum(np.array([2,1])*a, axis=1)
# Define dictionary with mapping
D = {0: 0, 1: 1, 2: 3, 3: 2}
# Apply dictionary
a = [D[x] for x in a]
You could use the successive pairs as indices to perform a look-up, for getting the translated value:
master = np.array([[0, 1],[3, 2]])
b = master[a[::2], a[1::2]]
Test input:
[1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1]
Output:
[2, 1, 2, 2, 1, 1, 0, 3]
