Set more sensibel values for parameter beam from twiss

cheetah/particles.py

@@ -497,12 +497,16 @@ def from_twiss(
             ), "Arguments must have the same shape."
 
         # Set default values without function call in function signature
-        beta_x = beta_x if beta_x is not None else torch.full(shape, 0.0)
+        beta_x = beta_x if beta_x is not None else torch.full(shape, 1.0)
         alpha_x = alpha_x if alpha_x is not None else torch.full(shape, 0.0)
-        emittance_x = emittance_x if emittance_x is not None else torch.full(shape, 0.0)
-        beta_y = beta_y if beta_y is not None else torch.full(shape, 0.0)
+        emittance_x = (
+            emittance_x if emittance_x is not None else torch.full(shape, 7.1971891e-13)
+        )
+        beta_y = beta_y if beta_y is not None else torch.full(shape, 1.0)
         alpha_y = alpha_y if alpha_y is not None else torch.full(shape, 0.0)
-        emittance_y = emittance_y if emittance_y is not None else torch.full(shape, 0.0)
+        emittance_y = (
+            emittance_y if emittance_y is not None else torch.full(shape, 7.1971891e-13)
+        )
         sigma_s = sigma_s if sigma_s is not None else torch.full(shape, 1e-6)
         sigma_p = sigma_p if sigma_p is not None else torch.full(shape, 1e-6)
         cor_s = cor_s if cor_s is not None else torch.full(shape, 0.0)