Re: Division by zero, despite strong hint
- To: mathgroup at smc.vnet.net
- Subject: [mg96576] Re: [mg96542] Division by zero, despite strong hint
- From: Bob Hanlon <hanlonr at cox.net>
- Date: Mon, 16 Feb 2009 16:38:58 -0500 (EST)
- Reply-to: hanlonr at cox.net
You left a comma out
g3[x_] := Piecewise[{{Sin[1/x], x != 0}, {0, x == 0}}]
Plot[g3[x], {x, 0, 1}, PlotStyle -> Red]
However, the second condition is unnecessary since the default is zero
g3[x_] := Piecewise[{{Sin[1/x], x != 0}}]
Plot[g3[x], {x, 0, 1}, PlotStyle -> Red]
Bob Hanlon
---- dch888 <dch888 at googlemail.com> wrote:
=============
Hi,
I'm trying to plot the Sin[1/x] curve with the curve being defined as
0 at 0 like this:
g3[x_] := Piecewise[{{Sin[1/x], x != 0} {0, x == 0}}]
Invoking Plot produced a flat graph; puzzled I asked for g3[0] and
got:
Power::infy Infinite expression 1/0 encountered >>
{
{Indeterminate, False True},
{0, \!\(\*
TagBox["True",
"PiecewiseDefault",
AutoDelete->False,
DeletionWarning->True]\)}
}
Hmmm... what's the trick here to stop Mathematica evaluating all the branches
of the piecewise fn? There's nothing in the documentation that I can
see to stop this in Piecewise... perhaps I need to use a different Mathematica
function?
Thanks,
David.