removed usage of the geometric_mean function native to Python 3.9 to run on...

removed usage of the geometric_mean function native to Python 3.9 to run on clusters with old Python.

bowtie.py

@@ -15,7 +15,6 @@ import matplotlib.colors as clr
 import matplotlib.pyplot as plt
 import numpy as np
 import plotutil as plu
-from statistics import geometric_mean
 
 
 def make_energy_grid(*, channels_per_decade=256, min_energy=0.01, max_energy=1.0E5):
@@ -292,10 +291,8 @@ def calculate_bowtie_gf(response_data,
     except ValueError:
         channel_energy_high = 0
 
-    # gf = np.mean(multi_geometric_factors_usable, axis = 0)  # Average geometric factor for all model spectra
-    # gf_cross = gf[bowtie_cross_index]  # The mean geometric factor for the bowtie crossing point
+    gf = np.mean(multi_geometric_factors_usable, axis = 0)  # Average geometric factor for all model spectra
+    gf_cross = gf[bowtie_cross_index]  # The mean geometric factor for the bowtie crossing point
 
-    gf_cross = geometric_mean(multi_geometric_factors_usable[:, bowtie_cross_index])
     energy_cross = energy_grid_local[bowtie_cross_index]
-
     return gf_cross, energy_cross, channel_energy_low, channel_energy_high