piecewise and if
- To: mathgroup at smc.vnet.net
- Subject: [mg128622] piecewise and if
- From: Jon Joseph <josco.jon at gmail.com>
- Date: Sat, 10 Nov 2012 02:08:52 -0500 (EST)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
- Delivered-to: l-mathgroup@wolfram.com
- Delivered-to: mathgroup-newout@smc.vnet.net
- Delivered-to: mathgroup-newsend@smc.vnet.net
I think these two functions should be the same but their plots show a clear difference:
f[x_, y_] := Exp[-1/(x^2 + y^2)] (* this function undefined at (0,0) *)
g[x_, y_] := Piecewise[{{0, x == 0 && y == 0}}, f[x, y]] (* Redefine so the hole is plugged *)
h[x_, y_] := If[x == 0 && y == 0, 0, f[x, y]] (* Another, I think, equivalent way to redefine f[x, y] *)
On my machine, "8.0 for Mac OS X x86 (64-bit) (October 5, 2011)"
when I
Plot3D[g[x, y], {x, -1,1}, {y, -1,1}]
Plot3D[h[x, y], {x, -1,1}, {y, -1,1}]
I see clear gaps along y=0 and x=0 for the g[x, y] plot and h[x, y] works properly. Am I misusing Piecewise?
Thanks, Jon.
- Follow-Ups:
- Re: piecewise and if
- From: Bob Hanlon <hanlonr357@gmail.com>
- Re: piecewise and if
- From: Bob Hanlon <hanlonr357@gmail.com>
- Re: piecewise and if