Re: BinomialDistribution
- To: mathgroup at smc.vnet.net
- Subject: [mg65229] Re: [mg65222] BinomialDistribution
- From: Bob Hanlon <hanlonr at cox.net>
- Date: Sun, 19 Mar 2006 03:19:06 -0500 (EST)
- Reply-to: hanlonr at cox.net
- Sender: owner-wri-mathgroup at wolfram.com
It is a precision problem
Needs["Statistics`DiscreteDistributions`"];
PDF[BinomialDistribution[101,u],26]
942094086221309585483304*(1 - u)^75*u^26
Use exact numbers
Integrate[PDF[BinomialDistribution[101,u],26],{u,0,29/100}]
933048986157861216695450243176853643798144899623811456319450
199150880460283695\
574163450094078155722758786878856490276554642606783152589583
543443098302366302\
35282827272057121761207307079176349327104941667/\
127500000000000000000000000000000000000000000000000000000000
000000000000000000\
000000000000000000000000000000000000000000000000000000000000
000000000000000000\
00000000000000000000000000000000000000000000000000
%//N
0.007318031263983225
or use NIntegrate
NIntegrate[PDF[BinomialDistribution[101,u],26],{u,0,0.29}]
0.007318031263983235
Bob Hanlon
>
> From: "Solomon, Joshua" <J.A.Solomon at city.ac.uk>
To: mathgroup at smc.vnet.net
> Subject: [mg65229] [mg65222] BinomialDistribution
>
> This makes me feel foolish.
> In[1]:=Needs["Statistics`DiscreteDistributions`"]
> In[2]:=Plot[PDF[BinomialDistribution[101,u],26],{u,0,0.5},PlotRange->All]
>
> This gives me a nice, bell-shaped curve, with a minimum of about 0 and a
> maximum of about .09. Let's integrate it from 0 to .29.
>
> In[3]:=Integrate[PDF[BinomialDistribution[101,u],26],{u,0,.29}]
> Out[3]=-0.612253
>
> How can this be negative?
>
>