On Tue, 2010-10-12 at 11:44 +0800, elaine kuo wrote:
> Dear list,
> I want to make a plot based on the following information, using the command
> plot.
>
> variable A for x axis : temperature (range: -20 degrees to 40 degree)
>
> variable B for y axis : altitude (range: 50 m to 2500 m )
Use the subset argument of plot():
## dummy data
dat <- data.frame(temperature = seq(-20, 40, by = 1),
altitude = seq(50, 2500, length = 61))
## use subset to select out the data we want
plot(altitude ~ temperature, data = dat, subset = temperature >= 0)
To understand what this is doing, consider:
with(dat, temperature >= 0)
So temperature >= 0 is yielding a logical vector indicating which rows
of dat are used to form the plot.
If you need to permanently subset your data, there is a subset function
that works the same way:
subset(dat, subset = temperature >= 0)
but yields a data frame of the rows of dat that matched the temperature
condition.
HTH
G
> The data below 0 degree of X variable wants to be erased tentatively.
>
> Please kindly advise the command to extract the data ranging from 0 degree
> to 40 degrees.
>
> Thank you.
>
>
>
> Elaine
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
--
%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%
Dr. Gavin Simpson [t] +44 (0)20 7679 0522
ECRC, UCL Geography, [f] +44 (0)20 7679 0565
Pearson Building, [e] gavin.simpsonATNOSPAMucl.ac.uk
Gower Street, London [w] http://www.ucl.ac.uk/~ucfagls/
UK. WC1E 6BT. [w] http://www.freshwaters.org.uk
%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
