[R] limits of a data frame size for reading into R

[Duncan Murdoch]

On 03/08/2010 1:10 PM, Dimitri Liakhovitski wrote:
> I understand the question I am about to ask is rather vague and
> depends on the task and my PC memory. However, I'll give it a try:
>
> Let's assume the goal is just to read in the data frame into R and
> then do some simple analyses with it (e.g., multiple regression of
> some variables onto some - just a few - variables).
>
> Is there a limit to the number of columns of a data frame that R can
> handle? I am asking because where I work many use SAS and they are
> running into the limit of >~13,700columns there.
>
> Since I am asking - is there a limit to the number of rows?
>
> Or is the correct way of asking the question: my PC's memory is X. The
> .txt tab-delimited file I am trying to read in has the size of YYY Mb,
> can I read it in?
>   

Besides what Jim said, there is a 2^31-1 limit on the number of elements 
in a vector.  Dataframes are vectors of vectors, so you can have at most 
2^31-1 rows and 2^31-1 columns.  Matrices are vectors, so they're 
limited to 2^31-1 elements in total. 

This is only likely to be a limitation on a 64 bit machine; in 32 bits 
you'll run out of memory first.

Duncan Murdoch