Matlab: using linterp to interpolate beach contours

[rocks rock]

Hi,

I am trying to create a plot of how certain elevation contours on a beach change over time. I have been using linterp for this so far. I want to interpolate a cross-shore (from dune to shoreline) position for a certain elevation from my data.

The issue I'm having is that when there is more than 1 occurrence of a particular contour on a particular profile linterp is picking up the landward most contour, but I want to know the location of the seaward most contour.

Any thoughts on a work around or another method of interpolation?

It was suggested to me that I try interp2, but I'm having trouble figuring out how to use that.

Thanks

 

[Pythagorean]

What's the nature of the data you're linterping, does it report the xyz of points along the surface? Do you encode this in a 3d matrix?

 

[rocks rock]

The data is a series of x and z points (y is assumed the same at all locations).

I think the problem was that linterp was sorting the data based on z before interpolating and we wanted to keep them in order by x.

Now using curveintersect, and it works!