Altair® Panopticon

### Cumulative Sum Percent

Cumulative Sum Percent calculates the cumulative sum of items in a group, sorted by a specified numeric column, divided by the total sum of all items in the group. This result is the cumulative sum expressed as a decimal value between 0 and 1, which can be formatted and presented as a percentage value.

For example, Cumulative Sum Percent is used when creating a Pareto Chart, where bars are sorted from largest to smallest, and a line is placed on top of the bars, using Cumulative Sum Percent as aggregation method for the line, sorted by the same numeric column as the bars, also from largest to smallest. The required sorting direction for the line and the Cumulative Sum Percent is achieved by creating a calculated column which is the numeric column used by the bars, multiplied by minus 1, to achieve a sorting from largest to smallest with regards to the original values, since the actual sorting has a non-configurable sort order from smallest to largest.

The example data below shows the result of Cumulative Sum Percent compared to Cumulative Sum. In this example, the total group sum of group A is 100 and the total group sum of group B is 100, for simplification.

 Group Item Value Cumulative Sum Cumulative Sum Percent A a1 35 35 0.35 A a2 29 64 0.64 A a3 23 87 0.87 A a4 8 95 0.95 A a5 5 100 1 B b1 55 55 0.55 B b2 21 76 0.76 B b3 12 88 0.88 B b4 8 96 0.96 B b5 4 100 1