Hi Ted,
Here's what the last example in ?contour says:
"## contourLines produces the same contour lines as contour"
So, even without digging into the source, I would guess
that your hunch is correct.
Cheers,
Peter Ehlers
(Ted Harding) wrote:> Hi Folks,
> I have been using contour() to produce some contour plots
> (of a spatially-smooted density produced by kde2d()), with
> very satisfactory results.
>
> I now want access to the coordinates of the points on the
> contours, and it would seem that contour() does not return a
> value, so there is nothing from which these could be extracted.
>
> However, apparently contourLines() does, and it seems to be
> invoked in essentially the same way (so far as the x,y,z
> and levels parameters are concerned).
>
> However, I am not sure whether the contour lines generated
> by contourLines() are the same numerically as those generated
> (at any rate plotted) by contour().
>
> By over-plotting the coordinates from contourLines() on the
> contours plotted by contour(), it looks as though they may be
> the same.
>
> Advice would be appreciated!
> With thanks,
> Ted.
>
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> E-Mail: (Ted Harding) <Ted.Harding at manchester.ac.uk>
> Fax-to-email: +44 (0)870 094 0861
> Date: 22-Oct-09 Time: 19:03:37
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