function formal_changepoint_analysis(input_data)
%this procedure has 3 steps: test whether there is a change in the data, establish when that change occurred, and get confidence intervals around the measured change
%first part, determining whether the input data contain a change, using a likelihood ratio test
%null_hyp= %no change point
%second part, assuming there is a change, determining when it occurred
%third part, using sampling with replacement of the original data, without altering the temporal structure, to get temporal confidence intervals
a=input_data
num_replacements=3
replacement_positions=round(rand*length(input_data))
%randomly determine how many values to replace
%randomly determine which values to use more than once
%randomly determine which values to remove to make room