Milton Cezar Ribeiro napsal(a):
Hello people,
I would like to know how can I use a list of variables (a char list) to have
access to the collums from a dataframe to be used in some analysis like, just
as example, a ploting task on a for() loop. Of course the code below is
just to understand the way. In this example I have a dataframe with several
collumns (more then fifty in my case) and I would like do use only some of
them. I really need use a var.list!
a-seq(1,100,1)
b-c(rep(c(1,2,3,4,5),20))
c-rnorm(100,0,1)
d-runif(100,0,1)
e-c^2
f-c/d
g-c-d
df-data.frame(cbind(a,b,c,d,e,f,g))
var.list-c(c,f,g)
for (myvar in var.list)
{
plot(density(df$myvar)) # here I need recover df$c , df$f and df$g
}
Kind regards
Miltinho
Brazil
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R-help@stat.math.ethz.ch mailing list
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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.
Is this what you expect?
for (myvar in var.list) {
plot(density(df[[paste(myvar)]]), main=paste('Density of',myvar))
}
It may not be bad idea to make a structure (list, dataframe) consisting
of only those variables you want and use some variant of apply() instead
of the for-loop. See ?apply, ?tapply, ?sapply
Petr
--
Petr Klasterecky
Dept. of Probability and Statistics
Charles University in Prague
Czech Republic
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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.
