Use pro Fit for data/function analysis, plotting, and curve fitting. It is used by scientists and engineers to analyze their measurements and the mathematical models they use to describe them. It comes with a spreadsheet editor for handling numeric and alphanumeric data sets of millions of rows and columns, a drawing editor for creating high quality graphs and presentations of data and functions, it allows for the flexible definition of custom mathematical functions using Python or Pascal, and it provides powerful curve fitting and data analysis tools. The application is scriptable with Apple Script, Python and Pascal, and user operations can be automatically recorded in these scripting languages.
See what's new in version 7 here