Fit a smooth closed shape through 4 points
Hi Allie, What is you goal here? Do you just want to plot a curve to the data? Do you want a function to approximate the data? You may find the functions spline() and splinefun() useful. Quick point though, with so few points you are only going to get a very rough approximation no matter the method used. Regards, Charles
On Mon, Mar 21, 2016 at 7:59 AM, Alexander Shenkin <ashenkin at ufl.edu> wrote:
Hello all,
I have sets of 4 x/y points through which I would like to fit closed,
smoothed shapes that go through those 4 points exactly. smooth.spline
doesn't like my data, since there are only 3 unique x points, and even
then, i'm not sure smooth.spline likes making closed shapes.
Might anyone else have suggestions for fitting algorithms I could employ?
Thanks,
Allie
shapepoints = structure(c(8.9, 0, -7.7, 0, 0, 2, 0, 3.8), .Dim = c(4L,
2L), .Dimnames = list(NULL, c("x", "y")))
smooth.spline(shapepoints)
# repeat the first point to close the shape
shapepoints = rbind(shapepoints, shapepoints[1,])
smooth.spline(shapepoints)
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