MATLAB Answers


How can I determine conditions and interpolate where necessary?

Asked by Stelios Fanourakis on 31 Oct 2019
Latest activity Commented on by Stelios Fanourakis on 1 Nov 2019
Assumingly we have a conditional state for most of the y values on axis and need to interpolate where necessary or where there are no conditions.
For example if we say that, while y = 3 then var = 5, what if y = 2.5, var = ??
We have information that for every y value equals to 3 the var is equal to 5 but we don't have information for y equals to 2.5 regarding the corresponding var value. In this case, an interpolation should come.
Can you please provide some code ideas?
Thank you


If you want to "interpolate" or "extrapolate", you should have more than one pair (y, var).
You must have a set of (y, var) pairs, and you would be able to find a missing pair , lets say (y1, var1), by means of an interpolation method.
So, what data exactly do you have?
I have x data which is the length of an object. Y data which is the height or the object's thickness. X data is same for both sets. Y axis data are different among sets. There is a third variable that is linked to y values. Y values are strain, 3rd variable is force and X is length of the object. Based on y values the force is changing. So different y values need to interpolate force values.

Sign in to comment.

1 Answer

Answer by Dimitris Kalogiros on 31 Oct 2019

A good solution for you problem is to use polynomial interpolation.

  1 Comment

I know polynomial interpolation as I have used it before for other of my tasks. It doesn't explain me how it will interpolate the force for every different y value. Even if there are 2 variables force/thickness (y values) how can this be linked with the stationary x values. X values do not change. They are the same. Only y values and forces are changing. But I think generally polynomials is a good idea. It just needs a small modification to suit my needs

Sign in to comment.