isoutlier Function, How window slides at edges.

I don't understand how "isoutlier" Functions window parameter slides. As an example:

WindowLength=10;
TF = isoutlier(MY_DATA,'movmedian',WindowLength);

To check last element of MY_DATA, window must exceed the boundaries of data. How "isoutlier" function overcome this problem ? Does it decrease window size at the start and end of the data, or use some kind of padding.

Thank you all !

Answer 1

[Shashank Gupta]

Hi,

Yes, there is change of window length at the edge cases, When you use "movmedian" methods to calulate the outliers, internally it uses the function movmedian to calculate the moving window median. And it does truncate the window length at the start and end. the algorithm depends upon the choice of Window length, if passed length is odd, the window is centered about the element in the current position. When length is even, the window is centered about the current and previous elements. The window size is automatically truncated at the endpoints when there are not enough elements to fill the window. When the window is truncated, the median is taken over only the elements that fill the window.

I hope this clear you confusion.

Cheers.

[Burak Ahmet Celebi]

Yess!

Thank you for your help