How to convert a table to a vector or list in R?

Asked Nov 23 '17 at 09:24

Active Nov 23 '17 at 14:48

Viewed 112 times

I have a table with two columns A,B and a lot of rows. Each value like a1 in A has a relation with some values like b1,b2,...,bk in B. In other words, my table is:

A   B
a1  b1
a1  b2
.
.
.
a1  bk
a2  b'1
a2  b'2
.
.
.
a2  b'k'
.
.
.

I was wondering how to convert this table to a list or vector in R. I converted my table to a file and used read.table function. Here is my code:

df <- read.table("MyData.csv", header = TRUE)
lapply(unique(df$A), function(x){
  paste0( x, ' = ', '(', paste( df[ df$A == x, ]$B, collapse = ","), ')' )
})

But the result of lapply has not any value. In fact, I want to show this table for each value in A in this format:

a1 = (b1, b2, ..., bk)
a2 = (b'1,b'2, ..., b'k')
.
.
.

edited Nov 23 '17 at 14:48

asked Nov 23 '17 at 09:24

Patris

How about `lapply(split(df1$B, df1$A), toString)` – akrun Nov 23 '17 at 09:25
It doesn't work, first argument of split must be a vector @akrun – Patris Nov 23 '17 at 09:49
Can you provide a reproducible example? – Sotos Nov 23 '17 at 10:00
It's easy, just set numerical value instead of a1,a2, b1, ... @Sotos – Patris Nov 23 '17 at 10:51
Sorry, No I won't. Just go over [How to make a great R reproducible example?](http://stackoverflow.com/questions/5963269) and post an example and also post the expected output. – Sotos Nov 23 '17 at 12:37
I edited my post @Sotos – Patris Nov 23 '17 at 14:49

How to convert a table to a vector or list in R?

0 Answers0