The program draws automatically more or less smooth lines passing through the measured data. You can modify the lines with the help of the mouse. Move the mouse pointer to the beta line where you want to correct and then press the left button. Two segments of the speed line are now being modified; use the mouse to reposition the lines. Release the button to fix the line in its new position.
Various views on the data are offered; For checking the smooth corrected flow lines the plot of Mach number over Pressure ratio is especially helpful. The subsonic part of the map is limited by a green line at Mach number 0.6.