[R] memory space

[Abelian]

Dear all
when the program is runing, we can realize that the memory size will
be asked more and more..
Therefore, we could meet the significant problem, such as  out off
memory size.
However, even if i rm() some variables that i will not use it anymore,
the memory size still not enough.
By the way, i found that if i turn off the R-gui, the program can work
again.
For example, i generate a 800*45000 matrix four times. however, when i
generate the fifth, the message tell me that the memory size is not
enough. So, i guess that maybe there are some way that can release the
memory  such that the memory size is ths same with the situation of
starting. Does anyone be able to provide the function to clean the
memory ? Thanks a lot.
Sincerely