In general, increasing the width and/or the repeat count makes smoothing more aggressive.
For classic “boxcar” (equal-weight moving average) smoothing, use odd widths (3, 5, 7, etc.) and leave repeat count = 1.
Use even widths for modified-boxcar smoothing (with first & last values given half-weight).
For moving-triangle smoothing, use odd widths and set repeat count = 2, except for minimal (width 3) moving-triangle smoothing, specify width = 2 and repeat count = 1.
This implementation also interpolates single missing months from the two adjacent months. (Consecutive missing months are not interpolated.)
To see precise weight values, hover your mouse cursor over the chart (or touch the chart on a touch-screen).
Click here for a downloadable, bookmarkable image of the weights bar-chart above (except in Internet Explorer or Microsoft Edge).