Before initiating the calculation, by the command Tools->Check drawing you can display a dialog window where, immediately after finishing any calculation the check drawing of the configuration of the set and calculated values will be displayed. The input points are black, the measured and calculated values red. The check drawing window is non-modal; therefore, it can be permanently open. Its position and size can be changed as needed. You can display individual points in it by dragging with a mouse from the coordinate list or from the calculation windows. Check drawing is described in detail in the manual under the topic Plug-ins.