[R] data mining & R

Ross Ihaka ihaka at stat.auckland.ac.nz
Fri Sep 8 05:37:37 CEST 2000


On Fri, Sep 08, 2000 at 10:23:34AM +0800, Mohd Zamri Murah wrote:
> I am new to R. currenty reading a few intereting articles about data mining.
> data mining, if I conclude right, is a method to analyze large data set.
> From the R-FAQ, it states that;
> 
>    R (currently) uses a _static_ memory model.  This means that when it
>    starts up, it asks the operating system to reserve a fixed amount of memory
>    for it.  The size of this chunk cannot be changed subsequently.  Hence, it
>    can happen that not enough memory was allocated, e.g., when trying to read
>    large data sets into R.
>    
> 
> out of curiousity, what is the upper limit of data size that R can process
> in term or number of rows/columns or in MBytes? Or, if this limit exist, is
> it hardware related? (e.g computer with 256MB can process more data than one
> with 64MB) 

This is about to change in 1.2.  Luke Tierney has rewritten the memory
management in R so that this restriction no longer applies.  On the other
hand, the computational model used within R is really only suitable for
data sets consisting of at most a few 10s of megabytes.  The problem is
that data sets are memory resident and some computations will copy the
entire data set.

	Ross
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-help-request at stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._



More information about the R-help mailing list