fix: change scv computation

src/estimate_statistics.jl

@@ -229,7 +229,7 @@ end
 """
 function scv(u::AbstractArray{T,N}; dims=:) where {T,N}
     I = abs2.(u)
-    var(I; dims, corrected=false) ./ mean(I; dims) .^ 2
+    mean(abs2, I; dims) ./ mean(I; dims) .^ 2 .- 1 # it might be advantageous to not use `var` to avoid computing the mean twice
 end