We have a calculated item as follows:
calculated-sum = last("item-1") + last("item-2") + last("item-3").
Now, if one of those items is nodata, the calculated-sum item is also nodata. This is ok, gerally speaking, but it is not what one would have expected in this particular case. We would like the sum to display the sum of the valid items and ignore absent items.
It could be corrected with a convertion from 'nodata' to zero in sums (or 'nodata' to ones in multiplications). Does anyone know a way of doing this?