converting string to a object name of a dataset
On Mar 18, 2011, at 11:18 AM, Madan Gopal Kundu wrote:
Hi, Thanks to David and Bendix for giving me the solution. I would like to extend my question little bit further. I am trying to execute following code: data1<- data.frame(x=c(1:4), y=rep(1:4))
Did you mean to type: data1<- data.frame(x=c(1:4), y=rep(1, 4)) # ? > data1 x y 1 1 1 2 2 1 3 3 1 4 4 1
gvars<- c("x", "y")
for (i in 1:2)
{
print(data1[[gvars[i]]])
}
and it returns the following output:
[1] 1 2 3 4
[1] 1 2 3 4
However, my desired output is
[1] 1 2 3 4
[1] 1 1 1 1
I tried the following code as well, but the problem remains same:
attach(data1)
for (i in 1:2)
{
print(get(gvars[i]))
}
Thanks in advance!!
Regards
Madan
On Fri, Mar 18, 2011 at 3:19 AM, BXC (Bendix Carstensen)
<bxc at steno.dk> wrote:
get() looks in the search path, so you can put data 1 there using attach():
data1<- data.frame(x=c(1:4), y=rep(1,4))
attach(data1)
gvars<- c("x", "y")
get( gvars[1] )
[1] 1 2 3 4
get( gvars[2] )
[1] 1 1 1 1 Best regards, Bendix Carstensen
_________________________________________
Bendix Carstensen
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-----Original Message-----
From: r-sig-epi-bounces at r-project.org
[mailto:r-sig-epi-bounces at r-project.org] On Behalf Of Madan
Gopal Kundu
Sent: 18. marts 2011 06:19
To: r-sig-epi at r-project.org
Subject: [R-sig-Epi] converting string to a object name of a dataset
Hi,
I am trying to access object which is variable of a dataset
using string. For that I am trying to convert a string to
the object name in the following code. But unfortunately it
looks something is going wrong in the following code.
data1<- data.frame(x=c(1:4), y=rep(1:4))
gvars<- c("x", "y")
z<- paste("data1", gvars[1], sep="$")
get(z)
The above code should return following output:
[1] 1 2 3 4
but instead it is printing following error "Error in get(z) :
object 'data1$x' not found"
Please help me to fix the problem.
Regards
Madan
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