R help - Aug 2007 - Problems using "lm" in combination with "predict"

Hello everybody,

I'm trying to predict a linear regression model but it does not work.

My Model: y = Worktime + Vacation + Illnes + Bankholidays

My modelmatrix is of dimension  28x4

Then I want to make use of the function predict because there
confidence.intervals are include.

My idea was:

mod <- lm(y~Worktime+Vacation+Illnes+Bankholidays)

newdate=data.frame(x=c(324,123,0.9,0.1))
predict(y,newdate)

But I always get the message:


'newdata' had 1 rows but variable(s) found have 28 rows


What can I do?

Yours, 

Maja

-- 
Psssst! Schon vom neuen GMX MultiMessenger geh?rt?
Der kanns mit allen: http://www.gmx.net/de/go/multimessenger

I think you need 

predict(mod,newdate)

instead of 

predict(y,newdate)


--- "Maja Schr?ter" <maja.schroeter at gmx.de> wrote:
> Hello everybody,
> 
> I'm trying to predict a linear regression model but it does not work.
> 
> My Model: y = Worktime + Vacation + Illnes + Bankholidays
> 
> My modelmatrix is of dimension  28x4
> 
> Then I want to make use of the function predict because there
> confidence.intervals are include.
> 
> My idea was:
> 
> mod <- lm(y~Worktime+Vacation+Illnes+Bankholidays)
> 
> newdate=data.frame(x=c(324,123,0.9,0.1))
> predict(y,newdate)
> 
> But I always get the message:
> 
> 
> 'newdata' had 1 rows but variable(s) found have 28 rows
> 
> 
> What can I do?
> 
> Yours, 
> 
> Maja
> 
> -- 
> Psssst! Schon vom neuen GMX MultiMessenger geh?rt?
> Der kanns mit allen: http://www.gmx.net/de/go/multimessenger
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
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> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>

> 
> My modelmatrix is of dimension  28x4
> 
> Then I want to make use of the function predict because there 
> confidence.intervals are include.
> 
> My idea was:
> 
> mod <- lm(y~Worktime+Vacation+Illnes+Bankholidays)
> 
> newdate=data.frame(x=c(324,123,0.9,0.1))

Perhaps you want to specify newdate like this

newdate=data.frame(Worktime = 324, Vacation = 123, Illness = 0.9, Bankholidays =
0.1))?



Best regards

Frede Aakmann T?gersen
Scientist


UNIVERSITY OF AARHUS
Faculty of Agricultural Sciences
Dept. of Genetics and Biotechnology
Blichers All? 20, P.O. BOX 50
DK-8830 Tjele

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