Re: Re: Odd behavior (bug?) with Exp[-x^2} and Erf
- To: mathgroup at smc.vnet.net
- Subject: [mg42980] Re: [mg42949] Re: Odd behavior (bug?) with Exp[-x^2} and Erf
- From: Peter Pein <peter1963 at totalise.co.uk>
- Date: Thu, 7 Aug 2003 00:53:37 -0400 (EDT)
- References: <200308050605.CAA01700@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Bill Rowe wrote:
>On 8/4/03 at 12:45 AM, siegman at stanford.edu (AES/newspost) wrote:
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>>Very reluctant to claim I've found a bug in Mathematica, but the
>>following cells certainly aren't doing what I expect them to:
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>> f[x_] = (Exp[-5(x + 1)^2] + Exp[-5x^2] + Exp[-5(x - 1)^2])^2
>> Plot[f[x], {x, 0, 2}, PlotRange -> {{0, 2}, {0, 2}}];
>> g[y_] = Integrate[f[x], {x, 0, y}, Assumptions -> y > 0]
>> Plot[g[y], {y, 0.001, 2}, PlotRange -> {{0, 2}, {0, 1}}];
>>
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>What do you see that you don't expect?
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Dear Bill,
since f[x]>0 for real x, nobody would expect g[y] to decrease anywhere.
Peter
P.S.: You might have got the latest version of Mathematica, but 4.x
shows odd (strange? weird!) behaviour.
- References:
- Re: Odd behavior (bug?) with Exp[-x^2} and Erf
- From: Bill Rowe <listuser@earthlink.net>
- Re: Odd behavior (bug?) with Exp[-x^2} and Erf