Marco Russo and Alberto Ferrari build a regression:
LINEST and LINESTX are two DAX functions that calculate a linear regression by using the Least Squares method. Both functions return multiple values, represented in a table that has a single row and one column for each of the values returned.
LINEST gets column references as arguments, whereas LINESTX explicitly iterates over the table provided in the first argument and executes the other arguments in a row context. Internally, LINEST invokes LINESTX and provides to it the table that contains the column references specified in the LINEST arguments. This article describes the more generic function LINESTX.
This is pretty neat for adding a visual element, though I’d probably include an R or Python visual and do the regression in there, myself.