Spatial derivative of the Boltzmann transformation.
Returns the partial derivative \(\partial o/\partial r\) evaluated at (r, t).
r (float or numpy.ndarray) – Location(s). If an array, it must have a shape broadcastable with t.
t (float or numpy.ndarray) – Time(s). If an array, it must have a shape broadcastable with r. Values must be positive.
do_dr – The return is a float if both r and t are floats. Otherwise it is an array of the shape that results from broadcasting r and t.
- Return type
float or numpy.ndarray