Re: How to integrate a function over a polygon
- To: mathgroup at smc.vnet.net
- Subject: [mg123309] Re: How to integrate a function over a polygon
- From: DrMajorBob <btreat1 at austin.rr.com>
- Date: Thu, 1 Dec 2011 05:50:35 -0500 (EST)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
- References: <201111291203.HAA05398@smc.vnet.net>
- Reply-to: drmajorbob at yahoo.com
When I plot that:
Plot3D[{x^2 + y^2, 0}, {x, -3, 3}, {y, -3, 3},
RegionFunction -> Function[{x, y, z}, 0 < x < 1 && 0 < y <= x]]
I see the 3D surface and, in addition, I see a triangle on the z == 0
plane marking the region.
I didn't expect the triangle. What am I missing in the documentation?
Bobby
On Wed, 30 Nov 2011 02:20:39 -0600, Andrzej Kozlowski <akoz at mimuw.edu.pl>
wrote:
>
> On 29 Nov 2011, at 13:03, Mikael wrote:
>
>> In a related question I wonder how one can plot g[x,y] over only the
> 2-dimensional unit simplex.
>
>
> Do you mean something like this:
>
> Plot3D[{x^2 + y^2, 0}, {x, -3, 3}, {y, -3, 3},
> RegionFunction -> Function[{x, y, z}, 0 < x < 1 && 0 < y <= x]]
>
> ?=
>
--
DrMajorBob at yahoo.com