Equations in Spartan

One of the more powerful tools in Spartan is the equation evaluator. This is used heavily in the spreadsheet, but also has important uses for atom labels and in plots. By default these equations are hidden, but one can use these equations to customize the look of spreadsheets and plots. For example, any cell and column header in the spreadsheet can be double-clicked and edited.

Equations in Spartan should be familiar to most Excel or Lotus users. The standard operators (+,-,*,/) are recognized and other columns can be referenced by name. If the column name has a space in it the name must be quoted using the double quote ("). Strings are quoted with single quotes ('). Built in functions are preceded by the @ symbol. The result of a function can be a real number or a string. For example the equation

Ekcal="E (kJ/mol)"*@kj2kcal
will take the value in the "E (kJ/mol)" column (presumably an energy) and multiply by 4.184 (the conversion from kcal to kJ).

The remaining part of this document provides in-depth discussions on particular strategies for using equations in Spartan.