Plot[ Evaluate@D[-E^-t^2, {t, 3}] , {t, -3, 3}] W. -----Original Message----- From: Bill Gosper Sent: Saturday, May 18, 2013 3:52 AM To: math-fun@mailman.xmission.com Subject: [math-fun] the tsunami function Minus the 3rd derivative of a bell curve: In[234]:= D[-E^-t^2, {t, 3}] Out[234]= -12 E^-t^2 t + 8 E^-t^2 t^3 In[235]:= Plot[%, {t, -3, 3}] looks remarkably like the water depth variation along the Tohoku coast during the 11-3-11 tsunami: Drawback, huge flood, huge backwash+drawback, lesser flood. Coincidence? I can supply YouTube URLs. --rwg Challenge: Combine %234 and %235 into a single "command". Macsyma has a similar problem. _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun