At change

Input 1 is a field. When the value of this field changes in the next record, then the value you enter in Input 2 is placed in the Result field of the next record. (Input 1 must be a field, either character or numeric, and Input 2 a constant.).

In the context of a drillhole interval or event file, for example, “At change” writes a value to the first record for each hole. Compare this with the “At last” function, which writes a value to the last record for each hole.

The difference between At change and At last is shown in the table below. In this case, Input 1 is the hole_id field and Input 2 is “1”.