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Co-authored-by: Martin Holters <[email protected]>

src/Filters/filt.jl

@@ -290,12 +290,12 @@ end
     filtfilt(b::AbstractVector, a::AbstractVector, x::AbstractArray)
 
 Filter `x` in the forward and reverse directions using either a
-`FilterCoefficients` object `coef`, or the filters `b` and / or `a`
+`FilterCoefficients` object `coef`, or the coefficients `b` and optionally `a`
 as in [`filt`](@ref). The initial state of the filter is computed so
 that its response to a step function is steady state. Before
 filtering, the data is extrapolated at both ends with an
 odd-symmetric extension of length
-`min(3*(max(length(b), length(a))-1), size(x, 1) - 1)`
+`min(3*(max(length(b), length(a))-1), size(x, 1) - 1)`.
 
 Because `filtfilt` applies the given filter twice, the effective
 filter order is twice the order of `coef`. The resulting signal has