R help - Aug 2005 - help on retrieving output from by( ) for regression

Hi all 

I used a function 
> qtrregr <- by(AB, AB$qtr, function(AB) lm(AB$X~AB$Y))
objective is to run a regression on quartery subsets in the data set
AB, having variables X and Y, grouped by variable qtr.

Now i retrieved the output using qtrregr, however it only showed the
coefficients (intercept and B) with out significant levels and
residuals for each qtr. Can some on help me on how can retrieve the
detailed regression output.

rgds

snvk

Look more carefully at 
?lm 
at the See Also section ...

X <- rnorm(30)
Y <- rnorm(30)
lm(Y~X)
summary(lm(Y~X))

Best,
Matthias

> Hi all 
> 
> I used a function 
> > qtrregr <- by(AB, AB$qtr, function(AB) lm(AB$X~AB$Y))
> 
> objective is to run a regression on quartery subsets in the 
> data set AB, having variables X and Y, grouped by variable qtr.
> 
> Now i retrieved the output using qtrregr, however it only 
> showed the coefficients (intercept and B) with out 
> significant levels and residuals for each qtr. Can some on 
> help me on how can retrieve the detailed regression output.
> 
> rgds
> 
> snvk
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list 
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read 
> the posting guide! http://www.R-project.org/posting-guide.html
>

Also, looking at the last example in ?by would be helpful:

attach(warpbreaks)
tmp <- by(warpbreaks, tension, function(x) lm(breaks ~ wool, data = x))

# To get coefficients:
sapply(tmp, coef)

# To get residuals:
sapply(tmp, resid)

# To get the model matrix:
sapply(tmp, model.matrix)



To get the summary() output, I suspect that using:

  lapply(tmp, summary)

would yield more familiar output as compared to using:

  sapply(tmp, summary)

The output from the latter might require a bit more "navigation"
through
the resultant matrix, depending upon how the output is to be ultimately
used.

HTH,

Marc Schwartz



On Thu, 2005-08-25 at 14:57 +0200, TEMPL Matthias wrote:
> Look more carefully at 
> ?lm 
> at the See Also section ...
> 
> X <- rnorm(30)
> Y <- rnorm(30)
> lm(Y~X)
> summary(lm(Y~X))
> 
> Best,
> Matthias
> 
> 
> > Hi all 
> > 
> > I used a function 
> > > qtrregr <- by(AB, AB$qtr, function(AB) lm(AB$X~AB$Y))
> > 
> > objective is to run a regression on quartery subsets in the 
> > data set AB, having variables X and Y, grouped by variable qtr.
> > 
> > Now i retrieved the output using qtrregr, however it only 
> > showed the coefficients (intercept and B) with out 
> > significant levels and residuals for each qtr. Can some on 
> > help me on how can retrieve the detailed regression output.
> > 
> > rgds
> > 
> > snvk
> >

What about using lmList from the lme4 package?

Randy


On 8/25/05 9:44 AM, "Marc Schwartz" <MSchwartz at mn.rr.com>
wrote:
> Also, looking at the last example in ?by would be helpful:
> 
> attach(warpbreaks)
> tmp <- by(warpbreaks, tension, function(x) lm(breaks ~ wool, data = x))
> 
> # To get coefficients:
> sapply(tmp, coef)
> 
> # To get residuals:
> sapply(tmp, resid)
> 
> # To get the model matrix:
> sapply(tmp, model.matrix)
> 
> 
> 
> To get the summary() output, I suspect that using:
> 
>   lapply(tmp, summary)
> 
> would yield more familiar output as compared to using:
> 
>   sapply(tmp, summary)
> 
> The output from the latter might require a bit more "navigation"
through
> the resultant matrix, depending upon how the output is to be ultimately
> used.
> 
> HTH,
> 
> Marc Schwartz
> 
> 
> 
> On Thu, 2005-08-25 at 14:57 +0200, TEMPL Matthias wrote:
>> Look more carefully at
>> ?lm 
>> at the See Also section ...
>> 
>> X <- rnorm(30)
>> Y <- rnorm(30)
>> lm(Y~X)
>> summary(lm(Y~X))
>> 
>> Best,
>> Matthias
>> 
>> 
>>> Hi all 
>>> 
>>> I used a function
>>>> qtrregr <- by(AB, AB$qtr, function(AB) lm(AB$X~AB$Y))
>>> 
>>> objective is to run a regression on quartery subsets in the
>>> data set AB, having variables X and Y, grouped by variable qtr.
>>> 
>>> Now i retrieved the output using qtrregr, however it only
>>> showed the coefficients (intercept and B) with out
>>> significant levels and residuals for each qtr. Can some on
>>> help me on how can retrieve the detailed regression output.
>>> 
>>> rgds
>>> 
>>> snvk
>>> 
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
http://www.R-project.org/posting-guide.html
> 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Randy Johnson
Laboratory of Genomic Diversity
NCI-Frederick
Bldg 560, Rm 11-85
Frederick, MD 21702
(301)846-1304
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~