tooltip - evaluate function at point

*To*: mathgroup at smc.vnet.net*Subject*: [mg98704] tooltip - evaluate function at point*From*: "Cristina Ballantine" <cballant at holycross.edu>*Date*: Thu, 16 Apr 2009 04:18:19 -0400 (EDT)

I would like to plot the solutions to an equation using ContourPlot and add a tooltip that evaluates a different function at the points on the solution. In particular, for the plot ContourPlot[Arg[Gamma[x + I*y]] == 0, {x, -10, 10}, {y, -10, 10}, PlotPoints -> 20] when the cursor is over a solution point I would like the ToolTip to display the value of Gamma at that point. Is this possible? If so, any suggestion is greatly appreciated. Cristina