Y = the dependent variable of the linear regression equation; the total number of counts observed in a time t . X = the independent variable of the linear regression equation; the observation number which is directly related to time. c = the intercept of the linear regression equation on the Y axis. Here c = f for stable, drift-, and oscillation-free data. m = the slope of the linear regression equation. Here m has a value close to m = 0 or m
