The task makes use of two possible methods for calculating the cumulative source counts (curve of growth) parameterised by the distance from the source centre. The switching between the two methods is controlled by the task integer parameter cumulativetype. The accepted valued of this parameter are 1 and 2, the first one being the default value. With cumulativetype=1, the number of counts in a circle with a radius equal to the distance from the source centre is calculated using the image pixels at the edge of this circle. With cumulativetype=2 the calculation is done straightforwardly by summing the pixel counts inside of the circle.