Construct a data.frame in a FOR-loop
Serguei Kaniovski wrote:
Say I have a FOR-loop for computing powers (just a trivial example)
for(i in 1:5)
{
x<-i^2
y<-i^3
}
How can I create a data.frame and a 3D plot of (i,x(i),y(i)), i.e. for
each iteration
First of all you can easily avoid for-loops in such examples.
You can better work with matrices, so just do
R> i <- 1:5
R> x <- i^2
R> y <- i^3
Second, maybe very interesting, if you want to look somethimg up and do
not know the R-command. You can always try with RSiteSearch("...").
I'm not sure what you mean with ``construct a data.frame in a for
loop''. As far as I know you can better first do the loop and construct
at the end the data.frame. Anyway, to create a data.frame, you can e.g. do
R> resdf <- as.data.frame(cbind(i,x,y))
To create 3D-plot there are seeral possibilities.
Try ?persp (for surfaces)
or you can download the scatterplot3d package available on CRAN (for
points and lines).
Hopefully this helps,
Good luck,
Kristel
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