diff --git a/ETA.py b/ETA.py
index f580f7e..9bd2774 100644
--- a/ETA.py
+++ b/ETA.py
@@ -442,7 +442,7 @@ else:
     if verbose:
         print( 'main ETA curved' )
 
-    if not cache_file.exists():
+    if not cache_file.exists() and not no_cache:
         if verbose:
             print( 'writing result in cache' )
         with shelve.open( str( cache_file ) ) as cache:
diff --git a/utils.py b/utils.py
index d3f7ead..5162430 100644
--- a/utils.py
+++ b/utils.py
@@ -276,3 +276,16 @@ def retrieve_peaks( data , window_size = 5 , error_coef = 1.05 , max_window_size
             peaks      = new_peaks
         window_size += 1
     return peaks
+def near_value( list_ , value ):
+    """
+    return indexes of the list whith a value nearest of the given
+    one when crossing it
+    """
+    change = np.where( np.diff( np.sign( list_ - value ) ) != 0 ) # sign change
+    index  = change + (
+        value - list_[ change ]
+    ) / (
+        list_[ change + np.ones_like( change ) ] - list_[ change ]
+    ) # interpolation
+    index = np.append( index , np.where( list_ == value ) )
+    return np.round( np.sort( index ) ).astype( int ) # triage