Function that splits the data into bins and computes the average in each bin
Bin_data(y, x, c = NULL, binsize = 0.2)
list with elements y_bin: list of average values of y in each bin, x_bin: list of middle points for each bin
is the outcome data
is the score data
specifies the cutoff point, set to NULL if the binning of the data should be independent from c
length of the interval that is one bin