[R] How to pass a variable to a function which use variable name as a parameter
There are functions which use variable names as parameters in some R
packages. However, if the variable name is stored in another variable, how
can I pass this variable to the function. Taking the rms package as an
example:
library(rms)
n - 1000
age - rnorm(n, 50, 10)
sex - factor(sample(c('female','male'), n,TRUE))
y - rnorm(n, 200, 25)
ddist - datadist(age, sex)
options(datadist='ddist')
fit - lrm(y ~ age)
Predict(fit, age, np=4)
options(datadist=NULL)
Here age was a variable name passed to Predict() function, but if age
was stored in variable var, that is, var - age, how can I pass var
to Predict() function? The purpose is that I want to change the parameter
of Predict() in a loop.
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Re: [R] How to pass a variable to a function which use variable name as a parameter
On Tue, May 26, 2015 at 5:14 AM, wong jane jane.wong...@gmail.com wrote:
There are functions which use variable names as parameters in some R
packages. However, if the variable name is stored in another variable, how
can I pass this variable to the function. Taking the rms package as an
example:
library(rms)
n - 1000
age - rnorm(n, 50, 10)
sex - factor(sample(c('female','male'), n,TRUE))
y - rnorm(n, 200, 25)
ddist - datadist(age, sex)
options(datadist='ddist')
fit - lrm(y ~ age)
Predict(fit, age, np=4)
options(datadist=NULL)
Here age was a variable name passed to Predict() function, but if age
was stored in variable var, that is, var - age, how can I pass var
to Predict() function? The purpose is that I want to change the parameter
of Predict() in a loop.
Please turn off HMTL email. The forum software doesn't really like it.
What you want is the get() function.
var-age
library(rms)
n - 1000
age - rnorm(n, 50, 10)
sex - factor(sample(c('female','male'), n,TRUE))
y - rnorm(n, 200, 25)
#
ddist - datadist(age, sex)
ddist - datadist(get(var),sex)
options(datadist='ddist')
fit - lrm(y ~ age)
#
Predict(fit, age, np=4)
Predict(fit,get(var),np=4)
options(datadist=NULL)
--
My sister opened a computer store in Hawaii. She sells C shells down by the
seashore.
If someone tell you that nothing is impossible:
Ask him to dribble a football.
He's about as useful as a wax frying pan.
10 to the 12th power microphones = 1 Megaphone
Maranatha!
John McKown
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and provide commented, minimal, self-contained, reproducible code.
Re: [R] How to pass a variable to a function which use variable name as a parameter
One way to use variable names in functions like Predict() that
do not evaluate their arguments in the standard way is to use
do.call() along with as.name(). E.g.,
varName-age
do.call(Predict, list(fit, as.name(varName), np=4))})
gives the same result as
Predict(fit, age, np=4)
Bill Dunlap
TIBCO Software
wdunlap tibco.com
On Tue, May 26, 2015 at 3:14 AM, wong jane jane.wong...@gmail.com wrote:
There are functions which use variable names as parameters in some R
packages. However, if the variable name is stored in another variable, how
can I pass this variable to the function. Taking the rms package as an
example:
library(rms)
n - 1000
age - rnorm(n, 50, 10)
sex - factor(sample(c('female','male'), n,TRUE))
y - rnorm(n, 200, 25)
ddist - datadist(age, sex)
options(datadist='ddist')
fit - lrm(y ~ age)
Predict(fit, age, np=4)
options(datadist=NULL)
Here age was a variable name passed to Predict() function, but if age
was stored in variable var, that is, var - age, how can I pass var
to Predict() function? The purpose is that I want to change the parameter
of Predict() in a loop.
[[alternative HTML version deleted]]
__
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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.
[[alternative HTML version deleted]]
__
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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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.
Re: [R] How to pass a variable to a function which use variable name as a parameter
On May 26, 2015, at 8:30 AM, William Dunlap wrote:
One way to use variable names in functions like Predict() that
do not evaluate their arguments in the standard way is to use
do.call() along with as.name(). E.g.,
varName-age
do.call(Predict, list(fit, as.name(varName), np=4))})
gives the same result as
Predict(fit, age, np=4)
Here's another approach, developed after looking at the code and the help page,
where I noticed that the factors argument was given an an alternate route for
specifying the variables for evaluation. The requirements for the 'factors'
argument are that it be provided as a named list and have either specific
values or NA.
var=age
vlist - list(dum=NA)
names(vlist)=var
Predict(fit, factors=vlist, np=4)
#- same result ---
age yhatlowerupper
1 25.04901 6.834836 4.856497 8.813174
2 41.14259 6.882369 4.919433 8.845306
3 57.23618 6.929903 4.967118 8.892688
4 73.32977 6.977437 4.999548 8.955325
Response variable (y): log odds
Limits are 0.95 confidence limits
--
David.
Bill Dunlap
TIBCO Software
wdunlap tibco.com
On Tue, May 26, 2015 at 3:14 AM, wong jane jane.wong...@gmail.com wrote:
There are functions which use variable names as parameters in some R
packages. However, if the variable name is stored in another variable, how
can I pass this variable to the function. Taking the rms package as an
example:
library(rms)
n - 1000
age - rnorm(n, 50, 10)
sex - factor(sample(c('female','male'), n,TRUE))
y - rnorm(n, 200, 25)
ddist - datadist(age, sex)
options(datadist='ddist')
fit - lrm(y ~ age)
Predict(fit, age, np=4)
options(datadist=NULL)
Here age was a variable name passed to Predict() function, but if age
was stored in variable var, that is, var - age, how can I pass var
to Predict() function? The purpose is that I want to change the parameter
of Predict() in a loop.
[[alternative HTML version deleted]]
--
David Winsemius
Alameda, CA, USA
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and provide commented, minimal, self-contained, reproducible code.
