Re: [R] quickly extract response from formula
Hi David,
thanks for your quick answer!
David Winsemius dwinsem...@comcast.net writes:
On Oct 31, 2013, at 1:27 PM, Andreas Leha wrote:
Hi all,
what is the recommended way to quickly (and without much burden on the
memory) extract the response from a formula?
If you want its expression value its just form[[2]]
If you wnat it evaluated in the environment of a dataframe then this should
be fairly efficient:
x - stats::runif(20)
y - stats::runif(20)
dfrm - data.frame(x=x,y=y)
extractResponse - function(frm, dat) { resp - frm[[2]]; print(resp) #
that's optional
fdat - eval(resp,
envir=dat); return(fdat) }
This is what I'll be using. Thanks again!
[...]
Regards,
Andreas
__
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Re: [R] quickly extract response from formula
You can bullet-proof it a bit by making sure that length(formula)==3
before assuming that formula[[2]] is the response. If length(formula)==2
then there is no response term, only predictor terms. E.g., replace
resp - frm[[2]]
with
resp - if (length(frm)==3) frm[[2]] else NULL
(or call stop(), or warning(), ...)
Bill Dunlap
Spotfire, TIBCO Software
wdunlap tibco.com
-Original Message-
From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On
Behalf
Of Andreas Leha
Sent: Friday, November 01, 2013 2:50 PM
To: r-h...@stat.math.ethz.ch
Subject: Re: [R] quickly extract response from formula
Hi David,
thanks for your quick answer!
David Winsemius dwinsem...@comcast.net writes:
On Oct 31, 2013, at 1:27 PM, Andreas Leha wrote:
Hi all,
what is the recommended way to quickly (and without much burden on the
memory) extract the response from a formula?
If you want its expression value its just form[[2]]
If you wnat it evaluated in the environment of a dataframe then this should
be fairly
efficient:
x - stats::runif(20)
y - stats::runif(20)
dfrm - data.frame(x=x,y=y)
extractResponse - function(frm, dat) { resp - frm[[2]]; print(resp) #
that's optional
fdat - eval(resp,
envir=dat); return(fdat) }
This is what I'll be using. Thanks again!
[...]
Regards,
Andreas
__
R-help@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.
__
R-help@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.
Re: [R] quickly extract response from formula
William Dunlap wdun...@tibco.com writes:
You can bullet-proof it a bit by making sure that length(formula)==3
before assuming that formula[[2]] is the response. If length(formula)==2
then there is no response term, only predictor terms. E.g., replace
resp - frm[[2]]
with
resp - if (length(frm)==3) frm[[2]] else NULL
(or call stop(), or warning(), ...)
Will do. Thanks.
- Andreas
Bill Dunlap
Spotfire, TIBCO Software
wdunlap tibco.com
-Original Message-
From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On
Behalf
Of Andreas Leha
Sent: Friday, November 01, 2013 2:50 PM
To: r-h...@stat.math.ethz.ch
Subject: Re: [R] quickly extract response from formula
Hi David,
thanks for your quick answer!
David Winsemius dwinsem...@comcast.net writes:
On Oct 31, 2013, at 1:27 PM, Andreas Leha wrote:
Hi all,
what is the recommended way to quickly (and without much burden on the
memory) extract the response from a formula?
If you want its expression value its just form[[2]]
If you wnat it evaluated in the environment of a dataframe then this
should be fairly
efficient:
x - stats::runif(20)
y - stats::runif(20)
dfrm - data.frame(x=x,y=y)
extractResponse - function(frm, dat) { resp - frm[[2]]; print(resp) #
that's optional
fdat - eval(resp,
envir=dat); return(fdat) }
This is what I'll be using. Thanks again!
[...]
Regards,
Andreas
__
R-help@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.
__
R-help@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.
[R] quickly extract response from formula
Hi all,
what is the recommended way to quickly (and without much burden on the
memory) extract the response from a formula?
The standard way to extract the response from a formula seems to be via
model.frame() or model.extract(), but that is very memory intensive.
Here is a quick example, that (BEWARE) consumes a lot of memory:
--8---cut here---start-8---
require(ALL)
data(ALL)
y - pData(ALL)$sex
x - t(exprs(ALL))
mf - cbind(as.data.frame(x), y=y)
extractResponse - function(formula, data)
{
m - match.call(expand.dots = FALSE)
m[[1L]] - quote(stats::model.frame)
m - eval.parent(m)
y - model.extract(m, response)
y
}
extractResponse(y~., data=mf)
extractResponseFast - function(formula, data)
{
y - eval(as.symbol(as.character(formula)[2]),
environment(formula))
y
}
extractResponseFast(y~., data=mf)
--8---cut here---end---8---
Or, to put my question differently, is the following approach
robust?
--8---cut here---start-8---
require(ALL)
data(ALL)
y - pData(ALL)$sex
x - t(exprs(ALL))
mf - cbind(as.data.frame(x), y=y)
extractResponseFast - function(formula, data)
{
y - eval(as.symbol(as.character(formula)[2]),
environment(formula))
y
}
extractResponseFast(y~., data=mf)
--8---cut here---end---8---
Many thanks in advance!
Regards,
Andreas
__
R-help@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.
Re: [R] quickly extract response from formula
On Oct 31, 2013, at 1:27 PM, Andreas Leha wrote:
Hi all,
what is the recommended way to quickly (and without much burden on the
memory) extract the response from a formula?
If you want its expression value its just form[[2]]
If you wnat it evaluated in the environment of a dataframe then this should be
fairly efficient:
x - stats::runif(20)
y - stats::runif(20)
dfrm - data.frame(x=x,y=y)
extractResponse - function(frm, dat) { resp - frm[[2]]; print(resp) # that's
optional
fdat - eval(resp, envir=dat);
return(fdat) }
extractResponse(y ~. , dat=dfrm)
y
[1] 0.80458147 0.90447989 0.54874785 0.04227895 0.11540969 0.98003767
0.37372573 0.58013515
[9] 0.47227247 0.22361616 0.45076628 0.57091106 0.36290661 0.69673890
0.87650224 0.96496587
[17] 0.14923759 0.25083936 0.32139801 0.91958308
The standard way to extract the response from a formula seems to be via
model.frame() or model.extract(), but that is very memory intensive.
Here is a quick example, that (BEWARE) consumes a lot of memory:
--8---cut here---start-8---
require(ALL)
data(ALL)
y - pData(ALL)$sex
x - t(exprs(ALL))
mf - cbind(as.data.frame(x), y=y)
extractResponse - function(formula, data)
{
m - match.call(expand.dots = FALSE)
m[[1L]] - quote(stats::model.frame)
m - eval.parent(m)
y - model.extract(m, response)
y
}
extractResponse(y~., data=mf)
extractResponseFast - function(formula, data)
{
y - eval(as.symbol(as.character(formula)[2]),
environment(formula))
y
}
extractResponseFast(y~., data=mf)
--8---cut here---end---8---
Or, to put my question differently, is the following approach
robust?
--8---cut here---start-8---
require(ALL)
data(ALL)
y - pData(ALL)$sex
x - t(exprs(ALL))
mf - cbind(as.data.frame(x), y=y)
extractResponseFast - function(formula, data)
{
y - eval(as.symbol(as.character(formula)[2]),
environment(formula))
y
}
extractResponseFast(y~., data=mf)
--8---cut here---end---8---
Many thanks in advance!
Regards,
Andreas
__
R-help@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.
David Winsemius
Alameda, CA, USA
__
R-help@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.
