Find neighboring values of a target value in array

Hi everybody,

I have a matrix, whose values represent the points of geometry-changes of a specific 3D geometry (mainly sorts of angularly aligned cuboids) in intervals. What I want to do is: enter a height, in which the geometry is analyzed. Afterwards, the 2D geometry in the user defined height is processed.

With my knowledge, I would achieve the solution with a combination of for-loop (heigth-direction entities of the matrix) and some if-conditions, but I am sure, there exists a more elegant solution for my problem.

Is there any function, which finds the two height-value neighbors in the matrix entities? Then, the interpolation part is not a problem any more.

Can anyone help me? Thanks in advance!

Best wishes, Georg

Answer 1

[Walter Roberson]

Depending on how your values are represented, slice() might be what you need.

[Georg Söllinger]

Hello Mr. Roberson,

Thanks for your reply! Actually, this function is not really what I need. I have z-Values arranged in an array together with x and y values, e.g.:

z = [7.200;16.715;36.245]
x = [...;...;...]
y = [...;...;...]

and e.g. a desired height of 30 -> the neighboring values in the array are 16.715 & 36.245. The function should either return the values or their array index.

[Walter Roberson]

 interp1(z, 1:length(z), height, 'previous')