R help - Jan 2008 - How to get out the t-test value matrix for a linear regression ?

Hi, all

     I've written some R script to calculate the linear regression of a
matrix.
Here below is my script:
>x<-matrix(scan("h:/data/xxx.dat",0),nrow=46,ncol=561,byrow=TRUE)
>year <- NULL
>year <- cbind(year,as.matrix(x[,1]))
>lm.sol<-lm(x~year)
>xtrend<-coef(lm.sol)[2,]    # get the matrix of regression coefficient 
>t.test<- ?                       # also want to get a similar matrix of
t-test value for the regression coefficient
>class(summary(lm.sol))      
> "listof"                           
>class(summary(lm.sol))
>"listof"                            # the t-test values are in the
obj "summary(lm.sol)", but how to get them out
                                         as a matrix similar as the
above"xtrend"?

Anyone can help me? Thanks !





Regards


Leo


2008-01-28 



leo_aries 

	[[alternative HTML version deleted]]

leo_aries wrote:
> Hi, all
>
>      I've written some R script to calculate the linear regression of a
matrix.
> Here below is my script:
>
>   
>>
x<-matrix(scan("h:/data/xxx.dat",0),nrow=46,ncol=561,byrow=TRUE)
>>     
>
>   
>> year <- NULL
>> year <- cbind(year,as.matrix(x[,1]))
>>     
>
>   
>> lm.sol<-lm(x~year)
>> xtrend<-coef(lm.sol)[2,]    # get the matrix of regression
coefficient
>>     
>
>   
>> t.test<- ?                       # also want to get a similar matrix
of t-test value for the regression coefficient
>>     
>
>   
>> class(summary(lm.sol))      
>> "listof"                           
>> class(summary(lm.sol))
>> "listof"                            # the t-test values are
in the obj "summary(lm.sol)", but how to get them out
>>     
>                                          as a matrix similar as the
above"xtrend"?
>
> Anyone can help me? Thanks !
>   
This seems to do it:
> Y <- matrix(rnorm(10),5)
> x <- rnorm(5)
> sapply(coef(summary(lm(Y~x))),"[", TRUE, "t value")
            Response Y1 Response Y2
(Intercept)   0.5485488    2.021065
x            -0.5175011   -2.225623

Or, a bit less sneaky
> sapply(coef(summary(lm(Y~x))), function(X) X[,"t value"])
            Response Y1 Response Y2
(Intercept)   0.5485488    2.021065
x            -0.5175011   -2.225623

-- 
   O__  ---- Peter Dalgaard             ?ster Farimagsgade 5, Entr.B
  c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
 (*) \(*) -- University of Copenhagen   Denmark          Ph:  (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)                  FAX: (+45) 35327907

Hi

r-help-bounces at r-project.org napsal dne 28.01.2008 17:16:37:
> Hi, all
> 
>      I've written some R script to calculate the linear regression of a
matrix.
> Here below is my script:
> 
>
>x<-matrix(scan("h:/data/xxx.dat",0),nrow=46,ncol=561,byrow=TRUE)
> 
> >year <- NULL
> >year <- cbind(year,as.matrix(x[,1]))
> 
> >lm.sol<-lm(x~year)
> >xtrend<-coef(lm.sol)[2,]    # get the matrix of regression
coefficient
> 
> >t.test<- ?                       # also want to get a similar matrix
of
t-
> test value for the regression coefficient
> 
> >class(summary(lm.sol)) 
> > "listof" 
> >class(summary(lm.sol))
> >"listof"                            # the t-test values are
in the obj
> "summary(lm.sol)", but how to get them out 
>                                          as a matrix similar as the 
above"xtrend"?
> 
str is your friend. Try,

str(summary(lm.sol))

and you will find a structure of summary object. 
>From it it is quite easy to find that
summary(lm.sol)$coef

gives you a table with t.test values.

Regards
Petr

> Anyone can help me? Thanks !
> 
> 
> 
> 
> 
> Regards
> 
> 
> Leo
> 
> 
> 2008-01-28 
> 
> 
> 
> leo_aries 
> 
>    [[alternative HTML version deleted]]
> 
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide 
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.