better negative power peak detection

rowers/dataprep.py

@@ -6,6 +6,7 @@ import rowingdata.tcxtools as tcxtools
 from rowers.utils import totaltime_sec_to_string
 from rowers.datautils import p0
 from scipy import optimize
+from scipy.signal import find_peaks
 from rowers.utils import calculate_age
 import datetime
 import gzip
@@ -1207,8 +1208,15 @@ def save_workout_database(f2, r, dosmooth=True, workouttype='rower',
     except KeyError:
         pass
 
-    # smoothen power
-    row.df[' Power (watts)'].replace(to_replace=0,method='ffill', inplace=True)
+
+    # remove negative power peaks
+    x = row.df[' Power (watts)'].values
+    x = x * - 1    
+    neg_peaks, _ = find_peaks(x, height=0) # hieght is the threshold value
+
+    row.df[' Power (watts)'][neg_peaks] = row.df[' Power (watts)'][neg_peaks-1]
+    
+    #row.df[' Power (watts)'].replace(to_replace=0,method='ffill', inplace=True)
 
     if dosmooth:
         # auto smoothing