[R] help: selection of data

[Martin Ballaschk]

Hi,

I'm not very experienced with R and struggle with data selection from a long
matrix with two columns.

I want to cut out the data between x > 0 and min(y).

> x <- c(-10, -5, 0, 5, 10, 15, 20)
> y <- c(10, 10, 10, -5, -6, -7, 10)
> data <- as.matrix( cbind(x, y) )

> data
       x  y
[1,] -10 10
[2,]  -5 10
[3,]   0 10 _
[4,]   5 -5  |-- data interval
[5,]  10 -6 _|   to be selected
[6,]  15 -7
[7,]  20 10


I need that to select the interval between a time 0 and a peak that is the
minimum here to fit that interval via nls() later.

Can anybody help? I would be very thankful for general hints how to select
data with the help of conditions.

Cheers
Martin