In DM2003, Calculator Dialog has several functions. First, unlike standard
Windows calculator, this tool allows you to evaluate arbitrary expression that
may depend on the set of variable parameters (see
expression syntax for more information about available functions and
operators). You may change values of a..z parameters using Parameters table and
calculate result for several parameter sets.

Another application of the Calculator Dialog related to the Plot and
Worksheet calculator tools. These tools use expression defined in the Calculator
Dialog that can be evaluated for clicked plot point or selected worksheet line.

For plot calculator, values of cx and cy parameters are X and Y
coordinates of the clicked plot point. Unlike the case of serie expressions,
in Calculator cx and cy parameter values are not X/Y column values but the
actual coordinates of the clicked point.

For worksheet calculator, values of a..z parameters are copied into the
parameter table from the columns of the selected worksheet line (cx and cy are
just aliases for columns marked as X and Y, and only existing columns are
copied). This tool works exactly as if you would click "Evaluate" button in
the Calculator dialog, but the Parameters table specially filled before
calculation. If you select more than one line, Worksheet calculator will be
disabled.