diff --git a/wavelength_calibration.py b/wavelength_calibration.py
index 3e954c6..b8b3752 100644
--- a/wavelength_calibration.py
+++ b/wavelength_calibration.py
@@ -62,7 +62,7 @@ peaks_inside = np.where(
     )
 )[0]
 if len( peaks_inside ) < 1:
-    raise Error( 'unknown plage, cannot autocalibrate' )
+    raise Exception( 'unknown plage, cannot autocalibrate' )
 first_peak_cal = peaks_inside[0]
 first_peak_ref = 3 # hard-coded
 
@@ -79,15 +79,52 @@ peaks_inside = np.where(
     argmin_1 < peaks_calib_top
 )[0]
 if len( peaks_inside ) < 1:
-    raise Error( 'unknown plage, cannot autocalibrate' )
+    raise Exception( 'unknown plage, cannot autocalibrate' )
 last_peak_cal = peaks_inside[0]
 last_peak_ref = 20 # hard-coded
 
-print( first_peak_cal , last_peak_cal )
+"""
+delete if too much peak in calib
+"""
+
+peaks_calib_top = peaks_calib_top[ first_peak_cal : last_peak_cal ]
+peaks_reference = peaks_reference[ first_peak_ref : last_peak_ref ]
+
+diff_ref  = ( peaks_reference[ 1 : ] - peaks_reference[ : -1 ] ).astype( float )
+diff_ref -= np.min( diff_ref )
+diff_ref /= np.max( diff_ref )
+diff_cal  = ( peaks_calib_top[ 1 : ] - peaks_calib_top[ : -1 ] ).astype( float )
+diff_cal -= np.min( diff_cal )
+diff_cal /= np.max( diff_cal )
+
+peaks = [ -1 ]
+for i in range( len( diff_ref ) ):
+    good , sum_ = -1 , 0
+    for j in range( peaks[ - 1 ] + 1 , len( diff_cal ) ):
+        sum_ += diff_cal[ j ]
+        if sum_ - diff_ref[ i ] >  0.002:
+            print( sum_ - diff_ref[ i ] )
+            raise Exception( 'reference peak not found' )
+        if sum_ - diff_ref[ i ] > - 0.002:
+            good = j
+            break
+    if good == -1:
+        raise Exception( 'reference peak not found and not exceeded' )
+    peaks.append( good )
+peaks.append( peaks[-1] + 1 )
+
+peaks_calib_top = np.array(
+    [ peaks_calib_top[ i ] for i in peaks[ 1 : ] ]
+).astype( int )
+
+"""
+Calibration
+"""
+
 polyval = np.polyfit(
-    peaks_calib_top[ first_peak_cal : last_peak_cal ],
-    peaks_reference[ first_peak_ref : last_peak_ref ],
-    1                                                ,
+    peaks_calib_top,
+    peaks_reference,
+    1              ,
 ) # We suppose there is as much calib peak than ref peak for now
 
 peaks_values = [ reference[ 1 , i ] for i in peaks_reference ]
@@ -144,3 +181,27 @@ manager.canvas.figure.gca().vlines(
 )
 manager.show()
 manager.start_main_loop()
+
+manager = qt.FigureManager(
+    qt.FigureCanvas(
+        fig.Figure(
+            figsize = ( 10 , 5 )
+        ),
+    ),
+    0,
+)
+
+manager.canvas.figure.add_subplot( 2 , 1 , 1 , xlim = ( 3800 , 4000 ) , xmargin = 0 ).plot(
+    wavelength    ,
+    mean_calib_top,
+)
+manager.canvas.figure.axes[0].set_title( 'raw data' )
+
+manager.canvas.figure.add_subplot( 2 , 1 , 2 , xlim = ( 3800 , 4000 ) , xmargin = 0 ).plot(
+    reference[0],
+    reference[1],
+)
+manager.canvas.figure.axes[1].set_title( 'reference' )
+
+manager.show()
+manager.start_main_loop()