*To*: mathgroup@smc.vnet.net*Subject*: [mg10704] Re: Bivariate Integrations/Assumptions error*From*: Paul Abbott <paul@physics.uwa.edu.au>*Date*: Fri, 30 Jan 1998 04:24:39 -0500*Organization*: University of Western Australia*References*: <6ahmj1$pf3@smc.vnet.net>

Mary Lesperance wrote: > Mathematica has trouble with bivariate integrations. I tried the > following: (The answer is 1 for any real Phi and Psi - this is just > the product of 2 normal densities) > > f[x_,y_,\[Phi]_,\[Psi]_,n_]:=.5*Exp[-.5*((x-\[Phi])^2 + (y-(\[Phi]^2 > + \[Psi]))^2)]/Pi Replacing the inexact 0.5 by the exact 1/2 works better: In[1]:=SetOptions[Integrate, GenerateConditions -> False]; In[2]:= Integrate[Exp[-(1/2)*((x - \[Phi])^2 + (y - (\[Phi]^2 + \[Psi]))^2)]/(2*Pi), {x, -Infinity, Infinity}, {y, -Infinity, Infinity}] Out[2]= 1 Cheers, Paul ____________________________________________________________________ Paul Abbott Phone: +61-8-9380-2734 Department of Physics Fax: +61-8-9380-1014 The University of Western Australia Nedlands WA 6907 mailto:paul@physics.uwa.edu.au AUSTRALIA http://www.pd.uwa.edu.au/~paul God IS a weakly left-handed dice player ____________________________________________________________________