differences between - Pacific Knowledge Systems

This function calculates the difference in an attribute value between successive numerical episodes. For example, we might define a Calculated Value

DeltaHDL = differences between HDL

This would appear in a case as follows:

               01 Jun 03    20 Jun 03    30 Jun 03    15 Oct 03    02 Nov 03
                 17:29        17:33        20:06        20:06        17:33
HDL               2.0          2.1          2.2          2.5          1.9
DeltaHDL                       0.1          0.1          0.3         -0.6
Trig              3.6                                    3.6
LipidDrug         N                         Y            Y

Note also the following expressions which are true for this case:

max differences between HDL = 0.3
min differences between HDL = -0.6

This function can also be used for determining rates of change.