Predicting weather conditions by extrapolating/interpolating previous data is one of the real use of simulation. Statistical theory tells us about the uncertainties in extrapolating from a sample to the frame. In this second case, extrapolating a plot estimates the radius of convergence. Thermodynamic modelling using the CALPHAD method requires extrapolating from binary and ternary systems. Extrapolating backwards, Ebolavirus and Marburgvirus probably diverged several thousand years ago. In 1994/1995, Jan Peczkis calculated a weight of forty tonnes extrapolating from limb bone circumference. LD values for humans are best estimated by extrapolating results from human cell cultures. Such drivers serve as leading indicators that are more accurate than simply extrapolating historical data. He expected this some time round 1800, extrapolating existing trends. Initially, extrapolating the GOES curve, it was estimated to be X28. Extrapolating the data to different situations has been 'problematic'. Extrapolating from data obtained in Edinburgh, Sharp et al. Extrapolating from this, Haas suggested that ankylosaurs ate relatively soft non-abrasive vegetation.