R help - Sep 2003 - Extracting objects from a list of matrix

Hello,

I would like to have an advise about how to extract objects from a list of
matrixs
I have fitted models (stored in an object called "model") using a
matrix
response and the same formula and data. I get back, from summary.lm, as many
sumarries as I have responses.
Thus I have extract the coefficient matrix for each model with the following
command :

coefficients(summary(model))

My goal is only to get the "t values" for each model. Generally to
extract a
colum from a matrix I do [,"t value"], and to apply a function to a
list I
use lapply. But here, I can not manage to extract the columns, since the
"[]" function, is not really a function with arguments ...

Can someone give me a solution ? (in avoiding to make a loop around my list
components).

Thanks in advance,

Isabelle.


Isabelle Zabalza-Mezghani
IFP - Reservoir Engineering Department
Rueil-Malmaison - France

ZABALZA-MEZGHANI Isabelle wrote:
> Hello,
> 
> I would like to have an advise about how to extract objects from a list of
> matrixs
> I have fitted models (stored in an object called "model") using a
matrix
> response and the same formula and data. I get back, from summary.lm, as
many
> sumarries as I have responses.
> Thus I have extract the coefficient matrix for each model with the
following
> command :
> 
> coefficients(summary(model))
> 
> My goal is only to get the "t values" for each model. Generally
to extract a
> colum from a matrix I do [,"t value"], and to apply a function to
a list I
> use lapply. But here, I can not manage to extract the columns, since the
> "[]" function, is not really a function with arguments ...
Why not? Try e.g.:

X <- matrix(1:4, 2)
"["(X,,2)

So in order to solve your problem try:

  lapply(YourList, "[", , "t-value")

or use an anonymous function:

  lapply(YourList, function(x) x[, "t-value"])


Uwe Ligges


> Can someone give me a solution ? (in avoiding to make a loop around my list
> components).
> 
> Thanks in advance,
> 
> Isabelle.
> 
> 
> Isabelle Zabalza-Mezghani
> IFP - Reservoir Engineering Department
> Rueil-Malmaison - France
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://www.stat.math.ethz.ch/mailman/listinfo/r-help


lapply(....., function(x) x[,"t value"])

On 19 Sep 2003 at 8:43, ZABALZA-MEZGHANI Isabelle wrote:

[
is a function:
> test <- list(a=1, b=2, c=3)
> "["(test,2)
$b
[1] 2


Kjetil Halvorsen
> Hello,
> 
> I would like to have an advise about how to extract objects from a list of
> matrixs
> I have fitted models (stored in an object called "model") using a
matrix
> response and the same formula and data. I get back, from summary.lm, as
many
> sumarries as I have responses.
> Thus I have extract the coefficient matrix for each model with the
following
> command :
> 
> coefficients(summary(model))
> 
> My goal is only to get the "t values" for each model. Generally
to extract a
> colum from a matrix I do [,"t value"], and to apply a function to
a list I
> use lapply. But here, I can not manage to extract the columns, since the
> "[]" function, is not really a function with arguments ...
> 
> Can someone give me a solution ? (in avoiding to make a loop around my list
> components).
> 
> Thanks in advance,
> 
> Isabelle.
> 
> 
> Isabelle Zabalza-Mezghani
> IFP - Reservoir Engineering Department
> Rueil-Malmaison - France
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://www.stat.math.ethz.ch/mailman/listinfo/r-help