diff --git a/function/utils.py b/function/utils.py
index 2aee6d5..c844689 100644
--- a/function/utils.py
+++ b/function/utils.py
@@ -210,12 +210,14 @@ def near_value( list_ , value ):
 
 def find_peak_low_high( list_ , value ):
     """
-    Return index of start and end of the biggest peak in a list
+    Return index of start and end of rise and descent of peaks crossing
+    a given value in a list
     """
     indexes = near_value(
         list_,
         value,
     )
+    old_list_ = list_
     list_ = np.gradient( list_ )
     if list_[ indexes[0] ] < 0:
         indexes.insert( 0 , 0 )
@@ -236,35 +238,123 @@ def find_peak_low_high( list_ , value ):
     descents = [
         indexes[ i ] for i in range( 1 , len( indexes ) , 2 )
     ]
-    np.where( list_[ : rises[0] ] < 0 )[-1]
-    np.where( list_[ descents[ i - 1 ] : rises[ i ] ] < 0 )[-1]
-    np.where( list_[ rises[ i - 1 ] : descents[ i ] ] < 0 )[-1]
-    first_rise    , last_rise    = indexes[0] , indexes[0]
-    first_descent , last_descent = indexes[1] , indexes[1]
-    min_diff = ( max( list_ ) - min( list_ ) ) * 0.001
-    max_high_value = max( list_ )
-    min_high_value = min( list_ )
-    max_low_value  = max( list_ )
-    min_low_value  = min( list_ )
-    while (
-        max_high_value - min_high_value > min_diff or
-        max_low_value  - min_low_value  > min_diff
-    ):
-        current_high = min_high_value + (
-            max_high_value - min_high_value
-        ) / 2
-        current_low  = min_low_value  + (
-            max_low_value  - min_low_value
-        ) / 2
-        indexes_high = near_value( list_ , current_high )
-        indexes_low  = near_value( list_ , current_low  )
-        if len( indexes_low ) != 2:
-            min_low_value  = current_low
-        else:
-            max_low_value  = current_low
-        if len( indexes_high ) != 2:
-            max_high_value = current_high
-        else:
-            min_high_value = current_high
 
-    return indexes_low, indexes_high
+    i = 0
+    start_rise = np.where( list_[ : rises[i] ] < 0 )
+    end_rise = rises[i] + np.where(
+        list_[ rises[i] : descents[i] ] < 0
+    )
+    start_descent = rises[i] + np.where(
+        list_[ rises[i] : descents[i] ] > 0
+    )
+    if len( rises ) == 1:
+        end_descent = descents[i] + np.where(
+            list_[ descents[i] : ] > 0
+        )
+    else:
+        end_descent = descents[i] + np.where(
+            list_[ descents[i] : rises[i + 1] ] > 0
+        )
+
+    if len( start_rise[0] ) == 0:
+        rise_starts = [ 0 ]
+    else:
+        rise_starts = [ start_rise[0][-1] ]
+    if len( end_rise[0] ) == 0:
+        rise_ends = [ rise_starts[0] ] # if first is a descent
+    else:
+        rise_ends = [ end_rise[0][0] ]
+    if len( start_descent[0] ) == 0:
+        descent_starts = [ rise_ends[0] ] # same
+    else:
+        descent_starts = [ start_descent[0][-1] ]
+    if len( end_descent[0] ) == 0:        # edge case:
+        descent_ends = [ descent_starts[0] ] # one pixel decrease
+    else:
+        descent_ends = [ end_descent[0][0] ]
+
+    while i < len( rises ) - 2: # last is i == len( rises ) - 2, works
+                                # if len( rises ) = 1 or 2
+        i += 1
+        start_rise = descents[i - 1 ] + np.where(
+            list_[ descents[i - 1] : rises[i] ] < 0
+        )
+        end_rise = rises[i] + np.where(
+            list_[ rises[i] : descents[i] ] < 0
+        )
+        start_descent = rises[i] + np.where(
+            list_[ rises[i] : descents[i] ] > 0
+        )
+        end_descent = descents[i] + np.where(
+            list_[ descents[i] : rises[i + 1] ] > 0
+        )
+
+        if len( start_rise[0] ) == 0:
+            rise_starts.append( descent_ends[-1] )
+        else:
+            rise_starts.append(
+                start_rise[0][-1] # last pixel that decrease
+            )
+        if len( end_rise[0] ) == 0:
+            rise_ends.append( rise_starts[-1] )
+        else:
+            rise_ends.append(
+                end_rise[0][0] # first pixel that decrease
+            )
+        if len( start_descent[0] ) == 0:
+            descent_starts.append( rises_ends[-1] )
+        else:
+            descent_starts.append(
+                start_descent[0][-1] # last pixel that increase
+            )
+        if len( end_descent[0] ) == 0:
+            descent_ends.append( descent_starts[-1] )
+        else:
+            descent_ends.append(
+                end_descent[0][0] # first pixel that increase
+            )
+    if i != 0 or len( rises ) != 1:
+        i += 1
+        start_rise = descents[i - 1] + np.where(
+            list_[ descents[i - 1] : rises[i] ] < 0
+        )
+        end_rise = rises[i] + np.where(
+            list_[ rises[i] : descents[i] ] < 0
+        )
+        start_descent = rises[i] + np.where(
+            list_[ rises[i] : descents[i] ] > 0
+        )
+        end_descent = descents[i] + np.where(
+            list_[ descents[i] : ] > 0
+        )
+
+        if len( start_rise[0] ) == 0:
+            rise_starts.append( descent_ends[-1] )
+        else:
+            rise_starts.append(
+                start_rise[0][-1] # last pixel that decrease
+            )
+        if len( end_rise[0] ) == 0:
+            rise_ends.append( rise_starts[-1] )
+        else:
+            rise_ends.append(
+                end_rise[0][0] # first pixel that decrease
+            )
+        if len( start_descent[0] ) == 0:
+            descent_starts.append( rises_ends[-1] )
+        else:
+            descent_starts.append(
+                start_descent[0][-1] # last pixel that increase
+            )
+        if len( end_descent[0] ) == 0:
+            descent_ends.append( descent_starts[-1] )
+        else:
+            descent_ends.append(
+                end_descent[0][0] # first pixel that increase
+            )
+    return [
+        rise_starts   ,
+        rise_ends     ,
+        descent_starts,
+        descent_ends  ,
+    ]