function [changepoint,changemagnitude]=find_change_point_using_trend_method(input_data)
%this is coded from a method by taylor, http://www.variation.com/cpa/tech/changepoint.html
%possible future additions include the consideration of a second candidate change point, to be identified at the same time as the first one
%see also change_point_analysis_trend_method_with_bootstrap

%change point analysis for variance also?

c=cumsum(input_data-mean(input_data));
%[maxval_original maxind_original]=max(c);
[minval_original minind_original]=min(c);
changepoint=minind_original;
changemagnitude=minval_original;  %alternative metric for change magnitude: diff_original=maxval_original-minval_original;