Merge pull request #4591 from lanzagar/fix-nomogram

[FIX] Nomogram: Fix crash on Python 3.8

Author: PrimozGodec

Orange/widgets/visualize/ownomogram.py

@@ -848,7 +848,7 @@ def calculate_log_reg_coefficients(self):
         if len(self.domain.class_var.values) == 2:
             self.b0 = np.hstack((self.b0 * (-1), self.b0))
             coeffs = np.vstack((coeffs * (-1), coeffs))
-        self.log_reg_coeffs = [coeffs[:, ranges[i]] for i in range(len(attrs))]
+        self.log_reg_coeffs = [coeffs[:, r] for r in ranges]
         self.log_reg_coeffs_orig = self.log_reg_coeffs.copy()
 
         min_values = nanmin(self.data.X, axis=0)
@@ -860,7 +860,7 @@ def calculate_log_reg_coefficients(self):
                 coef = self.log_reg_coeffs[i]
                 self.log_reg_coeffs[i] = np.hstack((coef * min_t, coef * max_t))
                 self.log_reg_cont_data_extremes.append(
-                    [sorted([min_t, max_t], reverse=(c < 0)) for c in coef])
+                    [sorted([min_t, max_t], reverse=(c < 0)) for c in coef.flat])
             else:
                 self.log_reg_cont_data_extremes.append([None])