Re: [R] how to loop through variables in R?
Hi!
You haven't got any answer probably because you didn't provide a
reproducible example. You can do it by copy/pasting the output of
dput(d) or dput(df).
Moreover, before this email, I couldn't really understand what you were
trying to do. It's not crystal clear now, but I think I got it.
First, when you read your txt, don't you already have the correct
data.frame? What is the difference between d and df? It looks like your
cbind() step is complicated. You can also index columns by their index
numbers.
So let's say you want in df the columns 1 to 5 and 6 to 8 from d. You
can do it like this:
sel - c(1:5,6:8) ## creates a vector with the columns indexes you want
to have in df
df - d[, sel] ## extract these columns from d and assign it into
df. Note the first comma!
You can also so it in one step of course:
df - d[, c(1:5,6:8)]
Second, in your loop, you overwrite at each iteration the result from
the previous one. You could do something like this:
result - numeric(length(df)) ## shouldn't it be length(df)-1?
for (i in 1:(length(df)-1)) {
result[i] - chisq.test(table(df[[i]], df[[i+1]])) ## each
computation will be stored in a different element of result
}
Next, chisq.test() returns a list, so it's not really a good idea to
store the output in a vector.
Take a look at
str(chisq.test(table(df[[1]], df[[2]])))
to know which element(s) you want to keep.
You would probably want something like this:
chisq.test(table(df[[1]], df[[2]]))[1:3]
So back to your loop!
result - vector(mode=list, length=length(df)) ## create a list,
shouldn't it here also be length(df)-1?
names(result) - paste(chisq_df[[, 1:length(df), ]]_df[[,
(1:length(df))+1, ]], sep=) ## that way, your list is named, which
is easier to remember what is
## what if you have lots of columns
for (i in 1:(length(df)-1)) {
result[[i]] - chisq.test(table(df[[i]], df[[i+1]]))[1:3] ## each
computation will be stored in a different element of the list
}
Is it what you're looking for?
HTH,
Ivan
Le 11/23/2010 03:11, wata...@post.com a écrit :
d-read.table(D:\\Working\\Statics.txt)
df- cbind(Q1, Q2, Q3, Q4, Q5, Q5A, Q5B, Q5C, Q5D, Q5E, Q5F, Q5G, Q6, Q6A, Q6B, Q6C, Q6D,
Q6E, Q6F, Q7, Q8, Q9)
#Than you can loop through them simply by doing:
result- numeric(length(df))
for (i in 1:(length(df)-1)) {
result- chisq.test(table(df[[i]], df[[i+1]]))
}
and then this error comes out:
Error: unexpected '}' in }
and how can I redirect the output of the chi-square test to a file instead of
console output?
[[alternative HTML version deleted]]
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--
Ivan CALANDRA
PhD Student
University of Hamburg
Biozentrum Grindel und Zoologisches Museum
Abt. Säugetiere
Martin-Luther-King-Platz 3
D-20146 Hamburg, GERMANY
+49(0)40 42838 6231
ivan.calan...@uni-hamburg.de
**
http://www.for771.uni-bonn.de
http://webapp5.rrz.uni-hamburg.de/mammals/eng/1525_8_1.php
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[R] how to loop through variables in R?
After importing a table with M variables and N records, I'd like to calculate chi-square statistics, say, between N1, N2; N1, N3, ..., N1, Ni, and then N2, N3, ... N2, Ni, ..., Ni-1, Ni. Two loops should be ok but the manual online help don't show a systematic way to do so but instead show hard-code examples so users have to type in the names themselves one by one... -- View this message in context: http://r.789695.n4.nabble.com/how-to-loop-through-variables-in-R-tp3053214p3053214.html Sent from the R help mailing list archive at Nabble.com. __ 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] how to loop through variables in R?
-Original Message- From: jas4710 wata...@post.com To: r-help@r-project.org Sent: Mon, Nov 22, 2010 4:11 pm Subject: [R] how to loop through variables in R? After importing a table with M variables and N records, I'd like to calculate chi-square statistics, say, between N1, N2; N1, N3, ..., N1, Ni, and then N2, N3, ... N2, Ni, ..., Ni-1, Ni. Two loops should be ok but the manual online help don't show a systematic way to do so but instead show hard-code examples so users have to type in the names themselves one by one... -- Sorry for typo. It should be N variables and M records. Thank you very much. [[alternative HTML version deleted]] __ 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] how to loop through variables in R?
wata...@post.com wrote: -Original Message- From: jas4710 wata...@post.com To: r-help@r-project.org Sent: Mon, Nov 22, 2010 4:11 pm Subject: [R] how to loop through variables in R? After importing a table with M variables and N records, I'd like to calculate chi-square statistics, say, between N1, N2; N1, N3, ..., N1, Ni, and then N2, N3, ... N2, Ni, ..., Ni-1, Ni. Two loops should be ok but the manual online help don't show a systematic way to do so but instead show hard-code examples so users have to type in the names themselves one by one... Sorry for typo. It should be N variables and M records. Thank you very much. Assuming you are working with a data frame df, and your variable with the name of a column in it is col1, you should be able to extract that column as a vector using df[[col1]]. And yes, the manual does describe this notation. __ 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] how to loop through variables in R?
-Original Message-
From: Yuliya Matveyeva yuliya.rm...@gmail.com
To: wata...@post.com
Sent: Mon, Nov 22, 2010 4:32 pm
Subject: Re: [R] how to loop through variables in R?
If you want to have a name-specific loop.
Assign names to your variables after inserting them into the data.frame like
that:
colnames(df) - c(var1,var23,var456,var44,...)
for (nam in colnames(df)) {
myfunction(df[[nam]])
}
Data.frames support access by names.
Unfortunately, in this sense I have to type in 1000 times... isn't there any
function that allows retrieving and assigning all columns automatically?
read.table in the R intro manual just brief says it can read a table but then
there's no follow up about how to access the data
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Re: [R] how to loop through variables in R?
d-read.table(D:\\Working\\Statics.txt)
df - cbind(Q1, Q2, Q3, Q4, Q5, Q5A, Q5B, Q5C, Q5D, Q5E,
Q5F, Q5G, Q6, Q6A, Q6B, Q6C, Q6D, Q6E, Q6F, Q7, Q8, Q9)
#Than you can loop through them simply by doing:
result - numeric(length(df))
for (i in 1:(length(df)-1)) {
result - chisq.test(table(df[[i]], df[[i+1]]))
}
and then this error comes out:
Error: unexpected '}' in }
and how can I redirect the output of the chi-square test to a file instead of
console output?
[[alternative HTML version deleted]]
__
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.
