In simulations of the collapse of gas clouds it is usual to start from a uniform sphere the evolution of which is determined by the two energy ratios = Thermal/Gravitational and = Rotational/Gravitational. In numerical calculations the two parameters are unfortunately supplemented by a number of unknown factors related to the exact numerical treatment of the collapse. It is therefore crucial to compare the results of several different methods before any judgement is made concerning the correct evolutionary track of the cloud.