Re: no data exclution and unique combination.

[MRAB]

On 24/07/2012 19:51, MRAB wrote:

On 24/07/2012 19:27, giuseppe.amatu...@gmail.com wrote:

Hi,
would like to take eliminate a specific number in an array and its 
correspondent in an other array, and vice-versa.

given

a=np.array([1,2,4,4,5,4,1,4,1,1,2,4])
b=np.array([1,2,3,5,4,4,1,3,2,1,3,4])

no_data_a=1
no_data_b=2

a_clean=array([4,4,5,4,4,4])
b_clean=array([3,5,4,4,3,4])

after i need to calculate unique combination in pairs to count the observations
and obtain
(4,3,2)
(4,5,1)
(5,4,1)
(4,4,2)

For the fist task i did

a_No_data_a = a[a != no_data_a]
b_No_data_a = b[a != no_data_a]

b_clean = b_No_data_a[b_No_data_a != no_data_b]
a_clean  = a_No_data_a[a_No_data_a != no_data_b]

but the results are not really stable.

mask = (a != no_data_a) & (b != no_data_b)
a_clean = a[mask]
b_clean = b[mask]

For the second task
The np.unique would solve the problem if it can be apply to a two arrays.

I couldn't figure out how to do the second part in numpy, so:

from collections import Counter
counts = Counter(zip(a_clean, b_clean))
counts = [pair + (count,) for pair, count in counts.items()]

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