Multiple plots question

Hello

I have a number of different data sets, each loaded as a matrix. I'd
like to plot them in a way that the data in the first column of each
matrix is plotted on the same pair of axes.

What I'm doing now is to call plot() for the data on the first matrix,
then call points() for the other ones. However, the axes are set by R
according to the data passed to plot(), and sometimes the data passed to
points() has larger values on the x axis, and the plot ends up being
"cut" (the y axis is not a problem since they're all probabilities).

Is there a way to dynamically adapt the axes so that all data can be
seen? I know I could build a new matrix with the columns I want to plot
but each matrix has 1 million rows, so I figure this would be
inefficient.

Do I have to check beforehand which column has the largest value and
call plot() on it, and then points() on the others, or is there an
automatic way to do this?

Thanks in advance,
Andre