|
A better option for a confidence interval for LD50
might be Fiellers method.
To see how to get the numbers from the object returned from dose.p,
use for example
str(object) or names(object).
Kjetil Halvorsen
-------Original Message-------
Date: Tuesday, December
31, 2002 7:17:39 PM
Subject: Re: [R] Probit
Analysis
Hi Andy,
Thanks! glm and dose.p can do exaclty
what I want to do. Just a quick
question,
how can I extract the
numbers in the glm.dose object created by the dose.p?
My
goal is to
calculate a 95% CI for the 'LD50'.
-
Jacqueline
apjaworski@mm
m.com To: "Ngayee J
Law" <[EMAIL PROTECTED]>
cc: [EMAIL PROTECTED]
12/31/2002 Subject: Re: [R] Probit Analysis
02:47 PM
Jacqueline,
This should be a simple
application of GLM. Check the help pages for glm,
family and dose.p in
library MASS. Look at the example at the bottom of
the dose.p help page
- it does almost exactly what you need.
Hope this
helps,
Andy
__________________________________
Andy
Jaworski
Engineering Systems Technology Center
3M Center,
518-1-01
St. Paul, MN 55144-1000
-----
E-mail: [EMAIL PROTECTED]
Tel: (651)
733-6092
Fax: (651)
736-3122
|---------+---------------------------------->
|
| "Ngayee J Law" |
| | <Ngayee.Law@celeradiagn|
| |
ostics.com> |
| | Sent by: |
| | [EMAIL PROTECTED].|
| |
ethz.ch |
| | |
| | |
| | 12/31/2002 16:17 |
| |
|
|---------+---------------------------------->
>
-----------------------------------------------------------------------------------------------------------------------------|
|
|
|
To: [EMAIL PROTECTED]
|
|
cc:
|
| Subject: [R] Probit
Analysis
|
>
-----------------------------------------------------------------------------------------------------------------------------|
Hello
all,
I have a very simple set of data and I would like to analyze
them with
probit analysis.
The data are:
X Event Trial
100
8 8
75 8 8
50 6 8
25 4 8
10 2 8
0 0 8
I want to
estimate the value of X that will give a 95% hit rate
(Event/Trial) and
the corresponding
95% CI. Anyone can offer some help? Thanks!!
-
Jacqueline
______________________________________________
[EMAIL PROTECTED]
mailing list
http://www.stat.math.ethz.ch/mailman/listinfo/r-help
______________________________________________
[EMAIL PROTECTED]
mailing list
http://www.stat.math.ethz.ch/mailman/listinfo/r-help
. | 
IncrediMail - Email has finally evolved -
Click
Here