EZplot® is an add-in for Excel that improves productivity by easily creating and updating many plots (50+) in seconds. Plots and calculations are defined with parameter names instead of cell locations. The user does not need to remember any commands because the user interface utilizes right-click menus to complement typed commands.
EZplot includes "Contour Plot", "Multy_Y" and many other capabilities that are not included in Excel. The Multy_Y program in EZplot is an enhanced version that allows for interactive plotting with Multiple Y axes plots.
EZplot provides formulas for 2D interpolation, 3D interpolation, and polynomials that can be used like any other Excel formula.