How can I combine the desired rows together in R

Question

For example, now I have:

A 1 1 1 1 3 4
B 1 8 9 7 9 6
A 2 3 4 5 6 6
C 1 1 1 1 1 1.

I want to get the rows with same letter A together, like this:

A 1 1 1 1 3 4
A 2 3 4 5 6 6

What should I do? It's in R programming.

the letters in front of every row is not the name of row, just the first element in each row

Please post a reproducible example of your data (for instance, are A, B, A, C a column or row names?). If you're trying to sort your data by the letter, you should check out the `order` function. — josliber, Sep 11 '14 at 21:53
@josilber, I doubt they are row names, as duplicate row names are not allowed. — David Arenburg, Sep 11 '14 at 22:05
@josilber, this is interesting, as it will generate an error if `mat` is a `data.frame` — David Arenburg, Sep 11 '14 at 22:13
sorry for the confusion. the letters in front of every row is not the name of row, just the first element in each row — Star Young, Sep 14 '14 at 20:14

Jaap · Answer 1 · 2014-09-15T16:59:29.363

0

You can use the order() function to do that:

# reading the data
df <- read.table(header=FALSE, text="A 1 1 1 1 3 4
B 1 8 9 7 9 6
A 2 3 4 5 6 6
C 1 1 1 1 1 1")

# ordering the data according to the values in the first colum
df[order(df[,1]),]

edited Sep 15 '14 at 16:59

answered Sep 12 '14 at 15:05

Jaap

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thank you, but it shows" error in df[,1], object of type 'closure' is not subsettable" – Star Young Sep 15 '14 at 14:50
I should have named the dataframe `df` instead of `dat`; see my updated answer. It should work now. – Jaap Sep 15 '14 at 17:01

How can I combine the desired rows together in R

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