I prepared a gdt file of the famous Galton data showing regression toward the mean (find the data description below). I propose adding this to the gretl's sample data files. Also attached is a plot of the data found somewhere over the net. I was wondering if it is possible to reproduce a similar graph using gretl. This would be useful. What would also be very very useful is the possibility to add any line (or a curve) to a graph by entering its formula in gretl's plot controls. Currently we can't even add a 45 degree line. Best regards Talha Francis Galton's Mid-parent Child Height Data Description: Galton's famous comparison of the heights of 928 adult children with those of their 205 pairs of parents. It shows that when the parents are taller than the median, their children tend to be shorter and when the parents are shorter than the median, their children tend to be taller. Galton termed this as "regression towards mediocrity." Variables: parent = Mid-parent height in inches (Range 64 - 73) child = Child height in inches (Range 61.7 - 73.7) Source: Galton, F., "Regression Towards Mediocrity in Hereditary Stature," Journal of the Anthropological Institute of Great Britain and Ireland, 15, 246--263, 1886. -- "Remember not only to say the right thing in the right place, but far more difficult still, to leave unsaid the wrong thing at the tempting moment." - Benjamin Franklin (1706-1790) --