I modified Prism's two-phase exponential decay equation to add a third phase. How can I display the half-times on the results sheet?

With the built-in equations, we went out of our way to put in the half-life values. We have not made a way to specify extra calculations to do when reporting results of user-defined equations. That is on our wish list for a future version.

One solution is to rewrite the equation so Prism fits half-life rather than rate constant. Thus a one-phase decay would be

Y = Ymax*exp((-1*ln(2)/HalfLife) * X)

The drawback, of course, is that Prism will no longer display the rate constant(s).