python - Average positive numbers in a row -

i have numpy matrix, , each row has combination of positive , negative numbers.

i want create new vector, gives me average of positive numbers in row in matrix.

for instance, if matrix:

[[1 2 3 -1]  [2 5 -6 5]] 

i want create vector values:

[[2]  [4]] 

what's fastest way so?

there positive numbers.

if it's guaranteed have @ least 1 positive number (>=0) per row, convert negative numbers (excluding 0) nans np.where , use np.nanmean along rows, -

np.nanmean(np.where(a>=0,a,np.nan),axis=1) 

sample run -

in [69]: out[69]:  array([[ 2,  3, -6, -6, -4],        [-5, -6, -1, -1,  3],        [-8,  5, -7, -9, -9],        [-3,  0,  7, -5, -6]])  in [70]: np.nanmean(np.where(a>=0,a,np.nan),axis=1) out[70]: array([ 2.5,  3. ,  5. ,  3.5])