[R] Additional field data collection

[stephen sefick]

This is a subset of a much larger dataframe.  I would like to be able
to automate finding the pair of x, y coordinates where the line
crosses zero agian

x <- (structure(list(bankfull_depths_m = c(0, 0.17, 0.38, 0.37, 0.36,
0.39, 0.47, 0.48, 0.19, 0.05, -0.05, -0.09), measurment_num_m = c(0.2,
0.4, 0.6, 0.8, 1, 1.2, 1.4, 1.6, 1.8, 2, 2.2, 2.4)), .Names =
c("bankfull_depths_m",
"measurment_num_m"), class = "data.frame", row.names = 97:108))

qplot(measurment_num_m, bankfull_depths_m, data=x)

in this case it is 2.1, 0

I need a way to process a whole bunch of data points, and I am at a
loss.  Thanks for any help.
regards,



-- 
Stephen Sefick

Let's not spend our time and resources thinking about things that are
so little or so large that all they really do for us is puff us up and
make us feel like gods.  We are mammals, and have not exhausted the
annoying little problems of being mammals.

								-K. Mullis