Re: mg[14547] Multiplying Piecewise Continuous Functions.

*To*: mathgroup at smc.vnet.net*Subject*: [mg14566] Re: mg[14547] Multiplying Piecewise Continuous Functions.*From*: Jack Goldberg <jackgold at math.lsa.umich.edu>*Date*: Fri, 30 Oct 1998 03:07:36 -0500*Sender*: owner-wri-mathgroup at wolfram.com

Sergio, You asked in mg[14547] whether it is possible to multiply two piecewise continuous (PC) functions together (both written in Which form) so that the answer is PC in the same form. Not only is the answer yes, but far more is possible and not difficult to do, because I managed to do it. One can add, subtract, multiply, integrate (the integral being the unique continuous anti-derivative function modulo an arbitrary additive constant). The general term of Fourier Series expansion of such functions is also easly found. I have mentioned this in an earlier post but didn"t think there was enough interest in posting the code. I have changed my mind and will post the code in the hopes that a good programmer will revise it so that it is suitable for inclusion in MathSource. In fact I was thinking of submitting an article on this very topic to one of the few journals devoted to Mathematica, but their publication frequency seems so erratic to me that I never got around to doing so. When was the last Mathematica Journal published? Jack Goldberg Dept. of Math University of Michigan Ann Arbor MI, 48109