# HG changeset patch
# User Nicolas Saunier <nicolas.saunier@polymtl.ca>
# Date 1648841944 14400
# Node ID 38f0d0ceac3f4309becc4adb78256bcc2ed0bd28
# Parent  0e5d37b0b9ffa7d5d70ba3781eaeaf840b3c12a6
issue with window length for savgol

diff -r 0e5d37b0b9ff -r 38f0d0ceac3f trafficintelligence/moving.py
--- a/trafficintelligence/moving.py	Fri Apr 01 15:33:22 2022 -0400
+++ b/trafficintelligence/moving.py	Fri Apr 01 15:39:04 2022 -0400
@@ -1564,12 +1564,17 @@
         else:
             return speeds
 
-    def getAccelerations(self, window_length, polyorder, delta=1.0, axis=-1, mode='interp', cval=0.0, speeds = None, nInstantsIgnoredAtEnds = 0):
+    def getAccelerations(self, window_length, polyorder, delta=1.0, axis=-1, mode='interp', cval=0.0, nInstantsIgnoredAtEnds = 0):
         '''Returns the 1-D acceleration from the 1-D speeds
         Caution about previously filtered data'''
-        if speeds is None:
-            speeds = self.getSpeeds(nInstantsIgnoredAtEnds)
-        return savgol_filter(speeds, min(window_length, len(speeds)), polyorder, 1, delta, axis, mode, cval)
+        speeds = self.getSpeeds(nInstantsIgnoredAtEnds)
+        if window_length > len(speeds):
+            wlength = min(window_length, len(speeds))
+            if wlength % 2 == 0:
+                wlength -=1
+        else:
+            wlength = window_length
+        return savgol_filter(speeds, wlength, polyorder, 1, delta, axis, mode, cval)
 
     def getSpeedIndicator(self):
         from indicators import SeverityIndicator