RuntimeWarning: invalid value encountered in arcsin gamma = np.arcsin(K*T/dt)

This warning occurs when the input argument to the numpy arcsin function is not within the valid range of -1 to 1. The output of the arcsin function will be a NaN (Not a Number) value in this case.

To fix this warning, you can check whether the input argument is within the valid range before calling the arcsin function. For example:

if abs(K*T/dt) > 1:
gamma = np.nan
else:
gamma = np.arcsin(K*T/dt)

This code first checks whether the absolute value of K*T/dt is greater than 1. If it is, then gamma is set to NaN. Otherwise, the arcsin function is called with the input argument K*T/dt.