LTB_Sclass_v2.py uses an alternative verson of the LTB geodesic equations. LTB_prac_v2.py is to be used with LTB_Sclass_v2.py. Note that the choice of z_vec i.e the vector of redshifts in the geodesic class might not be best. When angles are chosen such that the coordinate r(z) should decrease, it does decrease but than at some point turns around and start increasing again. The increase in redshift achieved for decreasing r(z) is about 0.5 whereas for increasing r(z) the redshift of 1100 or a time of last scattering of about 300,000 years is achieved. One has to be careful not to run below or above the range for coordinate r which was set on the grid of r and t when solving for the scale factor and its derivatives