Window calculations
Running totals, shares, differences, moving averages and rank, computed along the axis.
A window calculation is computed across the points a chart is already showing, in order. It needs an axis — a date or a category — because "the previous point" only means something once the points are in an order.
What is available
| Calculation | What it gives you |
|---|---|
| Running total | Each point plus everything before it |
| % of visible total | Each point as a share of what the chart shows |
| Difference | The change from the previous point |
| % change | That change as a percentage |
| Moving average | A smoothed line over a rolling window |
| Rank | Position within the visible points |
"% of visible total" means what it says
The denominator is what the chart is currently showing, so a slicer changes it. If you want a share of the true grand total regardless of filters, that is filter context, not a window calculation.
The name is deliberately explicit because the two get confused constantly, and the difference is the difference between a correct percentage and a confident wrong one.
Order is everything
A running total on an unsorted category axis is meaningless — it accumulates in whatever order the chart happens to draw. On a date axis it is exactly what you want. If a running total looks wrong, check what the axis is sorted by before checking the measure.
Where they cannot be used
A window calculation needs an axis, so it cannot go on a card, which has none. It also cannot be combined with subtotals. Both are refused explicitly rather than approximated.