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Fig. 3. Offline data analysis using polynomial regression to remove the circadian
rhythm from the pharmacological response. (A) The raw data are shown with a
fourth order polynomial least-squares regression fitted to segments of data
before the injection and after the treatment had worn off. The polynomial is
subtracted from the data to produce the residual data (B). A second, higher
order polynomial is fitted to the residual data. The peak response and 50%
peak response points are calculated for this polynomial.