SIDEBAR: Calculating the Bandpass Indicator
The bandpass indicator is an oscillator-type indicator using two filters. This sidebar give the formulas for using this indicator as described in John Ehler's article, in Excel.
In calculating the bandpass indicator, the first step is the calculation of the two Butterworth filters using
two different cutoff periods (P). Sidebar Figure 1 has the cutoff period 10 for filter 1 placed in cell I1, and
for filter 2, the cutoff period is 35 and is placed in cell L1. You can use any cutoff period your analysis