Re: Integrate[Exp[-(1-x)^2]/Sqrt[x],{x,0,Infinity}]
- To: mathgroup@smc.vnet.net
- Subject: [mg10621] Re: Integrate[Exp[-(1-x)^2]/Sqrt[x],{x,0,Infinity}]
- From: Allan Hayes <hay@haystack.demon.co.uk>
- Date: Tue, 27 Jan 1998 03:09:49 -0500
- References: <6a1rg4$q87@smc.vnet.net>
Andrea Bellettini wrote:
>
> Can someone explain the following behavior?
>
> In[48]:= $Version
>
> Out[48]= HP9000 Series 700 2.2 (May 7, 1993)
>
> In[49]:= Integrate[Exp[-(1-x)^2]/Sqrt[x],{x,0,Infinity}]
>
> On::none: Message SeriesData::csa not found.
>
> I 2 1 1
> Out[49]= - Sqrt[-] BesselK[-, -]
> 2 E 4 2
>
> In[50]:= N@%
>
> Out[50]= 0.411862 I
>
> In[51]:= NIntegrate[Exp[-(1-x)^2]/Sqrt[x],{x,0,Infinity}]
>
> Out[51]= 1.97373
>
> What is the meaning of csa?
Andrea:
Message SeriesData::csa not found
means that the message name SeriesData::csa was called but no associated
message was found.
>From the technical report Mathematica Warning Messages it seems that a message
Argument e in expr is not a power series
is normally generated when at least one of the arguments to ComposeSeries is
not a aeries (expression with head SeriesData).
This apparently shows up a bug - but all is well in Mathematica3.01:
Integrate[Exp[-(1-x)^2]/Sqrt[x],{x,0,Infinity}]
1 1 1 1
Pi (BesselI[-(-), -] + BesselI[-, -])
4 2 4 2
-------------------------------------
2 Sqrt[E]
N[%]
1.97373
NIntegrate[Exp[-(1-x)^2]/Sqrt[x],{x,0,Infinity}]
1.97373
--
Allan Hayes
Training and Consulting
Leicester, UK
hay@haystack.demon.co.uk
http://www.haystack.demon.co.uk
voice: +44 (0)116 271 4198
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