MATLAB: Error: Sample points must be unique and sorted in ascending order.

interpolationMATLAB

I have the following data. But when I am trying to interpolate it is giving

Error using matlab.internal.math.interp1

Sample points must be unique and sorted in ascending order.

Error in interp1 (line 154)

VqLite = matlab.internal.math.interp1(X,V,method,method,Xqcol)

Kindly help me out.

Thanks in advance.

You can use unique() to get rid of duplicate sample points. It will also sort them.

You need to use the optional output from the sort function that contains the sort order.

[Y, idx] = sort(time_series);
Zt = Zi(idx);

This error comes when there are duplicate points in input to 'interp1'.

You can remove duplicates using 'unique' function.

Example:-

>> [x, index] = unique(x); 
>> yi = interp1(x, y(index), xi);