rollback CenterConf to simple CDF of chi2 for 2 dof

package/lib/utils.py

@@ -109,7 +109,7 @@ def CenterConf(mask, PA, sPA):
 
     conf[np.isfinite(PA)] = 0.5 * np.exp(-0.5 * chi2[np.isfinite(PA)])
     c0 = np.unravel_index(np.argmax(conf), conf.shape)[::-1]
-    result = minimize(chisq, c0, bounds=[(0, PA.shape[1]), (0.0, PA.shape[0])], method="TNC")
+    result = minimize(chisq, c0, bounds=[(0, PA.shape[1]), (0.0, PA.shape[0])], method="trust-constr")
     if result.success:
         print("Center of emission found: reduced chi_squared {0:.2f}/{1:d}={2:.2f}".format(chisq(result.x) * (Nobs - 2), Nobs - 2, chisq(result.x)))
     else: