The function returns the value derivation of specified object of the Historical value type.

The function returns the value derivation of the object specified by the parameter archObject.

Derivation is the increase (decrease) in value per second and may be expressed as follows:

(curr. value - prev. value) / (curr. value time - prev. value time)

i.e. previous value subtracted from current one and the result is divided by the result of the previous value time subtracted from current value time.