Screen shot of a manual curve fitting example for the Hill equation in SDAR. The experimental data are shown as discrete plot with error bars in blue. The red curve is a fit of the Hill equation to the experimental data using the non-linear Simplex algorithm. The user can adjust the fit obtained by automated methods visually, using the sliders provided for each fit parameter (Manual Fit panel). The goodness-of-fit statistics are updated in real time and colour changes indicate whether the fit has improved or worsened. Also shown are the panels controlling which data set is to be worked on (Dataset panel) and which graphical properties are associated with a particular data set (Display Properties panel).