# How can I find the average between two points?

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Sandy on 20 Jul 2015
Commented: Sandy on 20 Jul 2015
So, I basically have a column of data composed of numbers and NaNs. I want my code to go through the column and wherever it finds an NaN, I want it to replace it with the average of the number before and after that NaN. For example:
Input:
23
45
64
NaN
32
Result:
23
45
64
48
32
David Schubert on 20 Jul 2015
input = [23; 45; 64; NaN; 32];
output = input;
idx = find(isnan(input));
output(idx) = (input(idx+1)+input(idx-1))/2
However this will only work if the first and the last elements are not NaN.
Sandy on 20 Jul 2015
Thank you!

Walter Roberson on 20 Jul 2015
idx = isnan(Input);
Result = Input;
Result(idx) = (Input(idx-1) + Input(idx+1)) / 2;
This depends upon the NaN not being the first or last entry.

David Schubert on 20 Jul 2015
input = [23; 45; 64; NaN; 32];
output = input;
idx = find(isnan(input));
output(idx) = (input(idx+1)+input(idx-1))/2
However this will only work if the first and the last elements are not NaN.