how we can measure the distance from a point on the neuron to soma? In other words, do we have a function in Neuron that returns the distance,"straight line", e.g, between soma and dend10[7]?
No. You have to define the xyz coordinates of a pair of points, one point on one section and
the other point on the other section. Then calculate the euclidian distance as
sqrt(delta x^2 + delta y^2 + delta z^2)