[R] threshold matrix

[Alaios]

Dear all,
I have a quite big matrix which I would like to threshold.
If the value is below threshold the cell should be zero
and 
if the value is over threshold the cell should be one

One really simple way to do that is two have a nested loop and check cell by cell.

The problem is that this seems to be really time consuming and ineficient.

What do you suggest me to try out?

I would like to thank you in advance for your help


Best Regards
Alex