[R] reading files with name columns and row columns

[Bert Gunter]

Please read the Help file carefully before posting:

"read.table is not the right tool for reading large matrices,
especially those with many columns: it is designed to read data frames
which may have columns of very different classes. Use scan instead for
matrices."

But the answer to your question can be found in

?make.names

for what constitutes a syntactically valid name in R.


Cheers,
Bert

Bert Gunter

"Data is not information. Information is not knowledge. And knowledge
is certainly not wisdom."
   -- Clifford Stoll


On Wed, Sep 2, 2015 at 3:11 PM, Bogdan Tanasa <tanasa at gmail.com> wrote:
> Dear all,
>
> would appreciate a piece of help with a simple question: I am reading in R
> a file that is formatted as a matrix (an example is shown below, although
> it is more complex, a matrix of 1000 * 1000 ):
>
> the names of the columns are 0, 10000, 40000, 80000, etc
> the names of the rows are 0, 10000, 40000, 80000, etc
>
>            0 200000 400000
> 0          0       0       0
> 200000  0       0       0
> 400000  0       0       0
>
> shall I use the command :
>
> y <- read.table("file",row.names=1, header=T)
>
> the results is :
>
>> y[1:3,1:3]
>        X0 X200000 X400000
> 0       0       0       0
> 200000  0       0       0
> 400000  0       0       0
>
> The question is : why R adds an X to the names of the columns eg X0,
> X20000, X40000, when it shall be only 0, 20000, 40000 ? thanks !
>
> -- bogdan
>
>         [[alternative HTML version deleted]]
>
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