Dear R-community,
I have a fitted bivariate polynomial, i.e:
fit = lm(cbind(x, y)~poly(t, 15))
and I would like to determine the length of the line in the interval t =
[a, b]. Obviously, I could use predict and go through all the points, i.e.
for (t in a:(b-1)) {
length = length + sqrt((x.pred[t] - x.pred[t+1])^2 + (y.pred[t] -
y.pred[t+1])^2)
}
but that would take very long given the amount of data I have. Do you know
of any better solutions?
Many thanks!
Nicolas
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