[R] read.table or read.csv without row index?

[Sarah Goslee]

Really, this depends on what you are trying to do. What's the underlying
problem you are solving? You can save a data frame to a file without
the names, if that's the real question, but I can't think of any reason to
not want names within R.

A matrix does not have to have row and column names, but a dataframe
is required to have them. If none are specified, sequential values will be
assigned.

> matrix(1:9, 3, 3)
     [,1] [,2] [,3]
[1,]    1    4    7
[2,]    2    5    8
[3,]    3    6    9
> data.frame(matrix(1:9, 3, 3))
  X1 X2 X3
1  1  4  7
2  2  5  8
3  3  6  9


Sarah


On Wed, Apr 22, 2009 at 10:00 AM, tsunhin wong <thjwong at gmail.com> wrote:
> Hello all,
>
> Probably my concepts about the data.frame and matrix and array in R
> are not clear, I need some clarification to help me understand them
> better.
>
>>M <- read.table("test1.csv",sep=",",row.names=NULL,header=T)
>
> gives me: M as
>
>  M1 M2 M3 M4 M5 M6 M7 M8 M9 M10
> 1  9 11 14 15 18 20 20 20 20  20
> 2  3  4  8  9 11 12 14 15 15  15
> 3  4  5  8  8  9  9  9  9  9   9
> 4  4  5  7  8  8  8  8  8  8   9
>
> 1. How can I read the csv file to:
>
>  M1 M2 M3 M4 M5 M6 M7 M8 M9 M10
> [1,]  9 11 14 15 18 20 20 20 20  20
> [2,]  3  4  8  9 11 12 14 15 15  15
> [3,]  4  5  8  8  9  9  9  9  9   9
> [4,]  4  5  7  8  8  8  8  8  8   9
>
> 2. or how can convert the above M to a format with [1,],[2,] etc
> instead of 1,2,etc?
>
> 3. How can I read a text file so that I can get:
>  [,1] [,2] [,3] [,4] [,5]
> [1,]  9 11 14 15 18
> [2,]  3  4  8  9 11
> [3,]  4  5  8  8  9
> [4,]  4  5  7  8  8
>
> (instead of having the columns names V1 to V5?)
>
> Thank you for your help!
>
> Regards,
>
>      John
>


-- 
Sarah Goslee
http://www.functionaldiversity.org