Fix

Author: giadarol

examples/bend_api/001_dev_rbend.py

@@ -1,38 +1,33 @@
 import xtrack as xt
 
-xt.RBend.from_dict({
-    "__class__": "RBend",
-    "edge_exit_angle_fdown": -7.065815087973354e-11,
-    "edge_entry_angle_fdown": -7.065815087973354e-11,
-    "extra": {
-     "polarity": -1.0
-    },
-    "prototype": "mbxf",
-    "order": 5,
-    "model": "adaptive",
-    "k0": -0.00023962580074486132,
-    "h": -0.00023962580074486132,
-    "length": 6.270000589737365,
-    "k0_from_h": False,
-    "angle": -0.001502453911986569,
-    "length_straight": 6.27
-   })
+bend1 = xt.RBend()
+bend1.angle = 0.1
+bend1.length_straight= 1.0
 
-breakpoint()
-bb = xt.RBend(**{
-    # "__class__": "RBend",
-    "edge_exit_angle_fdown": -7.065815087973354e-11,
-    "edge_entry_angle_fdown": -7.065815087973354e-11,
-    # "extra": {
-    #  "polarity": -1.0
-    # },
-    # "prototype": "mbxf",
-    "order": 5,
-    "model": "adaptive",
-    "k0": -0.00023962580074486132,
-    # "h": -0.00023962580074486132,
-    # "length": 6.270000589737365,
-    "k0_from_h": False,
-    "angle": -0.001502453911986569,
-    "length_straight": 6.27
-   }) 
+bend2 = xt.RBend()
+bend2.length_straight= 1.0
+bend2.angle = 0.1
+
+bend3 = xt.RBend(angle=0.1, length_straight=1.0)
+
+bend1d = xt.RBend.from_dict(bend1.to_dict())
+bend2d = xt.RBend.from_dict(bend2.to_dict())
+bend3d = xt.RBend.from_dict(bend3.to_dict())
+
+for bb in [bend1, bend2, bend3, bend1d, bend2d, bend3d]:
+    assert bb.h == 0.1 / bb.length
+    assert bb.k0 == 'from_h'
+    assert bb.k0_from_h == True
+    assert bb.length_straight == 1.0
+    assert bb.length > 1.0
+    assert bb.angle == 0.1
+
+bend1.k0 = 0.2
+assert bend1.k0 == 0.2
+assert bend1.h == 0.1 / bend1.length
+assert bend1.k0_from_h == False
+
+bend2.k0_from_h = False
+assert bend2.k0 == 0.
+assert bend2.h == 0.1 / bend2.length
+assert bend2.k0_from_h == False

xtrack/beam_elements/elements.py

@@ -1838,6 +1838,9 @@ def _update_rbend_h_length_k0(self):
         if abs(_angle) < 1e-10:
             length = _length_straight
             h = 0
+        elif abs(_length_straight) < 1e-10:
+            length = 0.0
+            h = 0
         else:
             h = (np.sin(theta_in) + np.sin(theta_out)) / _length_straight
             length = _angle / h