This function takes in a 3D array of values, effects or t_stats, etc. and returns a 2D matrix in which each entry contains a single value representing all corresponding entries in the 3rd dimension. This number is determined by the function specified by the user. It could be min, max, mean, etc.
flatten_array(arrayX, margin1, margin2, slice_fun)
A 2D matrix summarizing the input array
3D array of values, effects or t_stats, etc.
dimension that will end up as the columns of the final matrix
dimension that will end up as the rows of the final matrix
summary function. The function by which to summarize
the remaining dimension e.g., function(x) mean(x, na.rm = TRUE)