Angle calculations involve numerical integration over the source volume and detector surface “visible” by the source. Precision is defined by specifying the so called Gauss coefficient order (which is, actually, the number of integration segments in Gauss-Legendre numerical integration). Higher coefficient values result in higher precision, but longer calculations times. For large sources, the use of higher calculation precisions is advised.

Angle allows for the calculation precision values between 10 and 50. Recommended values, which will cover most cases, are between 25 and 35. The selected calculation precision is displayed in the “**Additional parameters**” group, both numerically and graphically.

To change calculation precision, click the “**Calculation precision**” option in the “**Additional parameters**” group, or choose the ribbon tab “**Additional parameters**” and then click the button “**Change calculation precision**”. In the calculation precision dialog simply drag the slider to the desired position and click the “**OK**” button.

New generations of computer processors allow for ever faster calculations. It is thus advisable not to “spare” on calculation precision if the corresponding calculation times are of no practical concern.