RuntimeWarning overflow encountered in scalar subtract if absHSIpixels10 - HSIpixels20 30

This warning message indicates that there was an overflow error when performing a scalar subtraction operation on the elements of two arrays, HSIpixels1 and HSIpixels2.

The warning is raised because the absolute difference between the first element of HSIpixels1 and HSIpixels2 is greater than 30, which is likely causing an overflow in the data type being used to store the result.

To fix this issue, you can consider using a larger data type (e.g., float64) to store the elements of the arrays, or you can try to normalize or scale the values of HSIpixels1 and HSIpixels2 before performing the subtraction operation