Re: Integrating over a Minimum

*To*: mathgroup at smc.vnet.net*Subject*: [mg32980] Re: [mg32946] Integrating over a Minimum*From*: Tomas Garza <tgarza01 at prodigy.net.mx>*Date*: Fri, 22 Feb 2002 01:49:11 -0500 (EST)*References*: <200202210706.CAA02149@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

I take the example you give. Try NIntegrate instead of Integrate: In[1]:= NIntegrate[Min[x, y], {y, 0, 1}, {x, 0, 1}] Out[1]= 0.33333 I quote from the Help Browser: "Integrate can evaluate integrals of rational functions. It can also evaluate integrals that involve exponential, logarithmic, trigonometric and inverse trigonometric functions, so long as the result comes out in terms of the same set of functions." If you're interested in numerical results - which I assume is the case - I think you can successfully use NIntegrate. Another example: In[1]:= f[x_, y_] := x + y /; 0 <= x <= 1 && 0 <= y <= 1; f[x_, y_] := x + 2*y /; x >= 1 || y >= 1; In[2]:= NIntegrate[f[x, y], {x, 0, 2}, {y, 0, 2}] Out[2]= 11.5 Tomas Garza Mexico City ----- Original Message ----- From: "Moritz Meyer-ter-Vehn" <meyerter at pool.uni-mannheim.de> To: mathgroup at smc.vnet.net Subject: [mg32980] [mg32946] Integrating over a Minimum > Hi, > > I want to integrate piecewise linear functions over a highdimensional > space. The ranges where the function is linear are given by linear > inequality constraints. > > Example: Integrate[Min[x,y],{y,0,1},{x,0,1}] > (of course that is not the one I really want to solve) > > I could not get matematica to do this. > > Moritz Meyer-ter-Vehn > >

**References**:**Integrating over a Minimum***From:*Moritz Meyer-ter-Vehn <meyerter@pool.uni-mannheim.de>