Results of the tests on model data presented as deviations of the found solution from true parameters of the model. Left to right: model systems referred to in the text and Table 1, from B5+B7 to F2+G0. The dashed vertical lines show the true value of each optimised parameter. The value found by the optimiser and the associated 1σ confidence interval are shown with the filled circle and shaded area, respectively. Each axis has a range of ±10% of true value so that the deviations may be visually compared between parameters and systems. An exception is made for the r₁ and r₂ pair of parameters for the last three systems, where axes had to be extended to accommodate large error bars (the numerical axes ticks should be used as guidance for these systems). Note: the masses of components are not optimised, they are computed from the optimised orbital parameters.