Re: Algorithm for distance from point to function

In article <qtfjb25k3ea0cvq344c9heq5lamcvq50dd@xxxxxxx>,
Mike.Prager <mike.prager¿@noaa.gov> wrote:
Terry wrote:

The minimum distance is the length of the shortest line from the point
x1y1 to a tangent to the line y=f(x).

Thanks to all who posted hints. We had indeed been planning
to use an optimization in finding the shortest distance. The
function to which we are finding distance is monotonic, and I
think that will simplify things a bit. It may even be
possible that we can use the derivative of the distance --
we'll have to examine that closely.

If you only use derivatives you'll miss any maxima/minima that are
either at end-points of the curve or at points where f(x) is not
differentiable, which can of course happen even if f is monotonic.

-- John Harper, School of Mathematics, Statistics and Computer Science,
Victoria University, PO Box 600, Wellington 6140, New Zealand
e-mail john.harper@xxxxxxxxx phone (+64)(4)463 5341 fax (+64)(4)463 5045
.

Relevant Pages

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