Dear all,

imagine you have a serie of points with a certain (fixed) coordinate between them. I then have an additional point which might end up sitting between 2 coordinates of the above mentioned serie. What is the best way to find the delta between the serie and the point?

Here’s an example:

Serie:

x y

0 2

1 4

2 5

3 7

4 9

Point:

x y

2.5 8

In this case the result should be the delta between 8 and the interpolated value of 2.5 from the serie between 2 and 3 hence: 8-6 = 2

Of course, I don’t know a priori where the point would end up being and I cannot simply use a linear interpolation of the whole serie. What I would need is a linear interpolation of the interval of the seri (0-1, 1-2 …) and the the delta between the point and this linear interpolation.

Thanks