numpy: Invalid value encountered in true_divide

Question

I have two numpy arrays and I am trying to divide one with the other and at the same time, I want to make sure that the entries where the divisor is 0, should just be replaced with 0.

So, I do something like:

log_norm_images = np.where(b_0 > 0, np.divide(diff_images, b_0), 0) 

This gives me a run time warning of:

RuntimeWarning: invalid value encountered in true_divide 

Now, I wanted to see what was going on and I did the following:

xx = np.isfinite(diff_images) print (xx[xx == False])  xx = np.isfinite(b_0) print (xx[xx == False]) 

However, both of these return empty arrays meaning that all the values in the arrays are finite. So, I am not sure where the invalid value is coming from. I am assuming checking b_0 > 0 in the np.where function takes care of the divide by 0.

The shape of the two arrays are (96, 96, 55, 64) and (96, 96, 55, 1)

Answer 1

You may have a NAN, INF, or NINF floating around somewhere. Try this:

np.isfinite(diff_images).all() np.isfinite(b_0).all() 

If one or both of those returns False, that's likely the cause of the runtime error.