diff --git a/knife_edge.py b/knife_edge.py
index 4fffc94adb9f0d1e6cadaa4b73b22f46d0ee7d3a..30a396950b7e7acea0908b963b97852e467ad48f 100644
--- a/knife_edge.py
+++ b/knife_edge.py
@@ -49,6 +49,8 @@ def knife_edge(nrun, axisKey='scannerX', signalKey='FastADC4peaks', p0=None, plo
         p0 = [np.mean(positions), 0.1, np.max(intensities)/2]
     popt, pcov = curve_fit(func, positions, intensities, p0=p0)
     print('w0 = (%.1f +/- %.1f) um'%(popt[1]*1e3, pcov[1,1]**0.5*1e3))
+    print('x0 = (%.3f +/- %.1f) mm'%(popt[0], pcov[0,0]**0.5*1e3))
+    print('a = %e +/- %e '%(popt[2], pcov[2,2]**0.5*1e3))
     
     if plot:
         xfit = np.linspace(positions.min(), positions.max(), 1000)