you can use dbinom but not rbinom. of course, if you have already written
your own dbinom, that's fine too: it's just one line function. you also
cannot use rt. is that clear?
Kosuke
On Sun, 23 Feb 2003, Ryan Davies wrote:
Do you mean that we can't use dbinom() either,
for 2a?
-Ryan
----- Original Message -----
From: "Kosuke Imai" <kimai(a)fas.harvard.edu>
To: "Phillip Y. Lipscy" <lipscy(a)fas.harvard.edu>
Cc: "Gov 2001" <gov2001-l(a)fas.harvard.edu>
Sent: Sunday, February 23, 2003 8:41 PM
Subject: Re: [gov2001-l] 2c question
Here are some clarification as to what built-in
functions you can and
cannot use. basically, you shouldn't use rbinom and rt.
2a. write your own function. don't use rbinom
2b. don't use dbeta.
2c. you can use rbeta and the function you wrote in 2a. don't use rbinom
3a. write your own function. don't use rt
3b. you can use the function you wrote in 2a. don't use rbinom
Kosuke
On Sun, 23 Feb 2003, Phillip Y. Lipscy wrote:
> We're running into trouble with taking draws from the beta distribution
on 2c.
> Our function for 2b gives us nice looking
curves, but when alpha & beta
< 1,
> the curve goes to infinity at the extremes.
So when we take draws from
the
> beta distribution, how are we to weigh the
probability of those infinite
> extremes? rbeta() seems to give a result consistent with the shape of
the
> curves - i.e.
>
> for (alpha & beta = really small) --> returns 0 and 1s
> for (alpha & beta = really big) --> returns values very close to 0.5
>
> Or, basically, is there a forumla for the probability mass function for
a
beta
distribution?
Thanks,
Phillip
-------------------------------------------------
Phillip Y. Lipscy
Perkins Hall Room #129
35 Oxford Street
Cambridge, MA 02138
(617)493-4893 DORM
(617)851-8220 CELL
lipscy(a)fas.harvard.edu
http://www.people.fas.harvard.edu/~lipscy/
First Year Student, Ph.D. Program
Harvard University, FAS, Department of Government
-------------------------------------------------
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