Prices can go up or down or falter in their movement. This code evaluates this by looking at two consecutive bars or sets of bars. If you put the set size to 1, the current and previous bar is evaluated. If put to 2, the last2 and the 2 before these are evaluated. Default is 12 because this seems to coincide with trend changes.
This code provides an advanced way to evaluate what the price does in a sort of three-value Boolean with the values up, down or falter. I use this code in indicators I develop where price direction is taken into account.
The simple output makes it possible to use it as an indicator on its own.