Statistical aggregation

In this example, we calculate the average, standard deviation, and kurtosis of a value in the table:

A more complex example uses window functions to calculate tumbling window statistical aggregates. The statistical aggregate is first calculated over each minute in the subquery and then the rolling aggregate is used to re-aggregate it over each 15 minute period preceding. The accessors remain the same as the previous example:

1D and 2D linear regression with statistical aggregates

The aggregate is available in two forms, a one-dimensional aggregate shown earlier in this section, and a two-dimensional aggregate. The two-dimensional aggregate takes in two variables (Y, X), which are dependent and independent variables respectively. The two-dimensional aggregate performs all the same calculations on each individual variable as performing separate one-dimensional aggregates would, and additionally performs linear regression on the two variables. Accessors for one-dimensional values append a _y or to the name. For example: