diff --git a/package/lib/utils.py b/package/lib/utils.py
index 86dcf8c..214f0f2 100755
--- a/package/lib/utils.py
+++ b/package/lib/utils.py
@@ -109,7 +109,7 @@ def CenterConf(mask, PA, sPA):
 
     conf[np.isfinite(PA)] = gammaincc(0.5, 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="trust-constr")
+    result = minimize(chisq, c0, bounds=[(0, PA.shape[1]), (0.0, PA.shape[0])], method="TNC")
     if result.success:
         print("Center of emission found")
     else:
diff --git a/package/src/emission_center.py b/package/src/emission_center.py
index c9fe314..097362c 100755
--- a/package/src/emission_center.py
+++ b/package/src/emission_center.py
@@ -23,7 +23,12 @@ def main(infile, P_cut=0.99, target=None, display="pf", output_dir=None):
     stkI = Stokes["I_STOKES"].data
     QN, UN, QN_ERR, UN_ERR = np.full((4, stkI.shape[0], stkI.shape[1]), np.nan)
     for sflux, nflux in zip(
-        [Stokes["Q_STOKES"].data, Stokes["U_STOKES"].data, np.sqrt(Stokes["IQU_COV_MATRIX"].data[1, 1]), np.sqrt(Stokes["IQU_COV_MATRIX"].data[2, 2])],
+        [
+            Stokes["Q_STOKES"].data,
+            Stokes["U_STOKES"].data,
+            np.sqrt(Stokes["IQU_COV_MATRIX"].data[1, 1]),
+            np.sqrt(Stokes["IQU_COV_MATRIX"].data[2, 2]),
+        ],
         [QN, UN, QN_ERR, UN_ERR],
     ):
         nflux[stkI > 0.0] = sflux[stkI > 0.0] / stkI[stkI > 0.0]
@@ -44,10 +49,25 @@ def main(infile, P_cut=0.99, target=None, display="pf", output_dir=None):
         target = Stokes[0].header["TARGNAME"]
 
     fig = figure(figsize=(8, 8.5), layout="constrained")
-    fig, ax = polarization_map(Stokes, P_cut=P_cut, step_vec=1, scale_vec=5, display=display, fig=fig, width=0.33, linewidth=0.5)
+    fig, ax = polarization_map(
+        Stokes,
+        P_cut=P_cut,
+        step_vec=1,
+        scale_vec=5,
+        display=display,
+        fig=fig,
+        width=0.33,
+        linewidth=0.5,
+    )
 
     ax.plot(*Stokescenter, marker="+", color="k", lw=3)
-    ax.plot(*Stokescenter, marker="+", color="red", lw=1.5, label="Best confidence for center: {0}".format(Stokespos.to_string("hmsdms")))
+    ax.plot(
+        *Stokescenter,
+        marker="+",
+        color="red",
+        lw=1.5,
+        label="Best confidence for center: {0}".format(Stokespos.to_string("hmsdms")),
+    )
     ax.contour(Stokescentconf, [0.01], colors="k", linewidths=3)
     confcentcont = ax.contour(Stokescentconf, [0.01], colors="red")
     # confcont = ax.contour(Stokesconf, [0.9905], colors="r")
@@ -62,11 +82,18 @@ def main(infile, P_cut=0.99, target=None, display="pf", output_dir=None):
     # handles.append(Rectangle((0, 0), 1, 1, fill=False, ls="--", ec=snr3cont.get_edgecolor()[0]))
     # labels.append(r"$SNR_P \geq$ 4  contour")
     # handles.append(Rectangle((0, 0), 1, 1, fill=False, ec=snr4cont.get_edgecolor()[0]))
-    ax.legend(handles=handles, labels=labels, bbox_to_anchor=(-0.05, -0.02, 1.10, 0.01), loc="upper left", mode="expand", borderaxespad=0.0)
+    ax.legend(
+        handles=handles,
+        labels=labels,
+        bbox_to_anchor=(-0.05, -0.02, 1.10, 0.01),
+        loc="upper left",
+        mode="expand",
+        borderaxespad=0.0,
+    )
 
     if output_dir is not None:
         filename = pathjoin(output_dir, "%s_center.pdf" % target)
-        fig.savefig(filename, bbox_inches='tight', dpi=300, facecolor="None")
+        fig.savefig(filename, bbox_inches="tight", dpi=300, facecolor="None")
         output.append(filename)
     show()
     return output
@@ -76,11 +103,57 @@ if __name__ == "__main__":
     import argparse
 
     parser = argparse.ArgumentParser(description="Look for the center of emission for a given reduced observation")
-    parser.add_argument("-t", "--target", metavar="targetname", required=False, help="the name of the target", type=str, default=None)
-    parser.add_argument("-f", "--file", metavar="path", required=False, help="The full or relative path to the data product", type=str, default=None)
-    parser.add_argument("-c", "--pcut", metavar="pcut", required=False, help="The polarization cut for the data mask", type=float, default=0.99)
-    parser.add_argument("-d", "--display", metavar="display", required=False, help="The map on which to display info", type=str, default="pf")
-    parser.add_argument("-o", "--output_dir", metavar="directory_path", required=False, help="output directory path for the plots", type=str, default="./data")
+    parser.add_argument(
+        "-t",
+        "--target",
+        metavar="targetname",
+        required=False,
+        help="the name of the target",
+        type=str,
+        default=None,
+    )
+    parser.add_argument(
+        "-f",
+        "--file",
+        metavar="path",
+        required=False,
+        help="The full or relative path to the data product",
+        type=str,
+        default=None,
+    )
+    parser.add_argument(
+        "-c",
+        "--pcut",
+        metavar="pcut",
+        required=False,
+        help="The polarization cut for the data mask",
+        type=float,
+        default=0.99,
+    )
+    parser.add_argument(
+        "-d",
+        "--display",
+        metavar="display",
+        required=False,
+        help="The map on which to display info",
+        type=str,
+        default="pf",
+    )
+    parser.add_argument(
+        "-o",
+        "--output_dir",
+        metavar="directory_path",
+        required=False,
+        help="output directory path for the plots",
+        type=str,
+        default="./data",
+    )
     args = parser.parse_args()
-    exitcode = main(infile=args.file, P_cut=args.pcut, target=args.target, display=args.display, output_dir=args.output_dir)
+    exitcode = main(
+        infile=args.file,
+        P_cut=args.pcut,
+        target=args.target,
+        display=args.display,
+        output_dir=args.output_dir,
+    )
     print("Written to: ", exitcode)