fix monotonic slope calculation

fslaborg · Apr 24, 2020 · 1043d25 · 1043d25
1 parent c3e879d
commit 1043d25
Showing 1 changed file with 1 addition and 4 deletions.
diff --git a/src/FSharp.Stats/Interpolation/CubicSpline.fs b/src/FSharp.Stats/Interpolation/CubicSpline.fs
@@ -473,10 +473,7 @@ module CubicSpline =
                 let rec loop i acc =
                     if i = x_Data.Length - 1 then
                         let s1 = (3. * (y_Data.[i] - y_Data.[i-1])) / (2. * (x_Data.[i] - x_Data.[i-1]))
-                        let s2 = 
-                            let s21 = (y_Data.[i-1] - y_Data.[i]) / (x_Data.[i-1] - x_Data.[i])
-                            let s22 = (y_Data.[i-1] - y_Data.[i-2]) / (x_Data.[i-1] - x_Data.[i-2])
-                            (s21 + s22) / 4.
+                        let s2 = calcSlope (i-1) / 2.
                         let tmp = s1 - s2
                         (tmp::acc) |> List.rev
                     else