[R] predict.glm - how to?

2006-03-02 Thread Laurits Søgaard Nielsen
Hi

I have a little R problem. I have created a GLM model in R and now I want to
predict some values outside the values I have in the model (extrapolate).

I have this code:

fitted.model4 - glm(Yval ~ time, family=gaussian, data=Fuel)

The question is - How do I predict a value of Yval ie with a value of time =
340 and also get confidence/prediction intervals for Yvar?

I have tried the predict.glm but cannot make it work - any suggestions how
to do this using predict.glm?



Yval are 312 fuel prices ranging from 60 to 140 and time is a sequence from
1 to 312.

The GLM summary output is as follows:

Deviance Residuals: 
Min   1Q   Median   3Q  Max  
-24.978   -4.033   -0.3914.747   15.323  

Coefficients:
 Estimate Std. Error t value Pr(|t|)
(Intercept) 79.698229   0.871830   91.42   2e-16 ***
seq(1:312)  0.180127   0.004828   37.31   2e-16 ***
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 

(Dispersion parameter for gaussian family taken to be 59.00219)

Null deviance: 100408  on 311  degrees of freedom
Residual deviance:  18291  on 310  degrees of freedom
AIC: 2161.6

Number of Fisher Scoring iterations: 2

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Re: [R] predict.glm - how to?

2006-03-02 Thread Paul Johnson
On 3/2/06, Laurits Søgaard Nielsen [EMAIL PROTECTED] wrote:
 Hi

 I have a little R problem. I have created a GLM model in R and now I want to
 predict some values outside the values I have in the model (extrapolate).


myglm - glm( some stuff here)
whatever - some-new-hypothetical-data-you-create
predict (myglm, newdata=whatever, type=response)

I have hints on this in Rtips

http://pj.freefaculty.org/R/Rtips.html#7.5


--
Paul E. Johnson
Professor, Political Science
1541 Lilac Lane, Room 504
University of Kansas

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[R] predict.glm and continous variables

2005-03-15 Thread line
Hello.
I am using the predict function to transform logit values from a glm to 
probabilities, (predict(model,type=response,se=T))..
Everything is going very well for the categorical variables where I get 
one value for the slope of each level and one value for standard error 
for each level.
The problem occurs when I whant to do the same for my continous 
variables. Instead of getting one value for the slope and and one value 
of SE for each variable (like what pops up in the summary in a 
univariate glm) I get a slope and SE value for every datapoint in the 
variable.

I hope someone knows the solution to my problem.
Regards,
Line.
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[R] predict.glm

2004-12-29 Thread Rajdeep Das
Hi All,

Sorry for this is a very naive question. 

I am trying to do binary classification (male vs female)  using glm using 
following data:

X1X2X3Class
2.34.52.1Male
0.93.2   1.6 Male
1.71.82.6Feamle



I am trying to use predict.glm for prediction with type=respose which gives 
the predicted probabilities as per documentation. 

My question is: which of the two classes does this probability corresponds to? 
My understanding is that it is the probability of the class that each of the 
new data has. Is that correct?

Thanks.

Raj
[[alternative HTML version deleted]]

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RE: [R] predict.glm

2004-12-29 Thread John Fox
Dear Raj,

I'm not sure that I'm interpreting your question properly, but I'll give it
a shot: When you use a two-level factor as the response variable in a
binomial GLM, the first level is taken to represent failure and the second
success. See ?glm for details. The default order of levels is
alphabetical, so unless you did something to order the levels differently,
Male would correspond to success and Female to failure. Thus the fitted
probability would be the probability of Male.

Is that what you wanted to know?

John


John Fox
Department of Sociology
McMaster University
Hamilton, Ontario
Canada L8S 4M4
905-525-9140x23604
http://socserv.mcmaster.ca/jfox 
 

 -Original Message-
 From: [EMAIL PROTECTED] 
 [mailto:[EMAIL PROTECTED] On Behalf Of Rajdeep Das
 Sent: Wednesday, December 29, 2004 1:33 PM
 To: R Help Mailing List
 Subject: [R] predict.glm
 
 Hi All,
 
 Sorry for this is a very naive question. 
 
 I am trying to do binary classification (male vs female)  
 using glm using following data:
 
 X1X2X3Class
 2.34.52.1Male
 0.93.2   1.6 Male
 1.71.82.6Feamle
 
 
 
 I am trying to use predict.glm for prediction with 
 type=respose which gives the predicted probabilities as per 
 documentation. 
 
 My question is: which of the two classes does this 
 probability corresponds to? My understanding is that it is 
 the probability of the class that each of the new data has. 
 Is that correct?
 
 Thanks.
 
 Raj
   [[alternative HTML version deleted]]
 
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[R] predict.glm(glm.ob,type=terms)

2003-06-04 Thread orkun
hello

pgeo-predict.glm(glm.ob,type=resp) works fine.

But I need to get predictions values in terms of each factor variables.
pgeo-predict.glm(glm.ob,type=terms)
gives Error in rep(1/n,n) %*% model.matrix(object): non conformable
arguments
Could anyone tell me why ?

Ahmet Temiz
Turkey
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