deletions | additions       diff --git a/fit_iter.md b/fit_iter.md  index 1f79430..cff03f9 100644  --- a/fit_iter.md  +++ b/fit_iter.md 
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First, the highest ranked regions are fitted with the extended fit function. After parameter optimization with the signal in the region is fitted with a linear model. For both models the corrected Akaike Information Criterion (AICc \cite{Burnham_2004}) is calculated and the region is taken to contain an event only if the AICc for the fit function is less than the AICc for the line. This ensures that the fit obtained with the fit function is good enough to justify the use of a more complicated model. After this each the fits are subtracted from the original signal. This allows the lower ranked regions to be fitted with reduced interference from higher ranking regions (see supporting info figures). When all regions have been fitted and their fits subtracted from the signal, the remaining signal is fitted with a polynomial function to approximate the baseline fluorescence.  In the second stage signals from regions are fitted again. Before performing the fit, the baseline and previously obtained fits for other regions are subtracted from the raw signal. This allows the simpler fit function to be used as subtraction eliminates the need for  the extra offset baseline  parameters (B and C). Once region is fitted in this manner the results  are no longer needed. subtracted from the raw signal to estimate the baseline again. If the relative change between the first and second fit stage is large then stage 2 is repeated.