Implemented class method to initialize OrientedCurveXYZFourier from C…

…urveXYZFourier

src/simsopt/geo/curve.py

@@ -635,6 +635,12 @@ def __init__(self, curve, phi, flip):
                  [0, 0, -1]])
         self.rotmatT = self.rotmat.T.copy()
 
+    def change_curve(self, new_curve):
+        if isinstance(self.curve, RotatedCurve):
+            self.curve.change_curve(new_curve)
+        else:
+            self.curve = new_curve
+
     def get_dofs(self):
         """
         RotatedCurve does not have any dofs of its own.

src/simsopt/geo/orientedcurve.py

@@ -142,4 +142,19 @@ def _make_names(self):
             for j in range(0, self.order):
                 dofs_name += [f'{c}s({j+1})', f'{c}c({j+1})']
         return xyc_name + ypr_name + dofs_name
+
+    @classmethod
+    def from_curvexyzfourier(cls, xyzcurve):
+        oriented_curve = cls(xyzcurve.quadpoints, xyzcurve.order)
+
+        for dname in xyzcurve.local_full_dof_names:
+            if dname in ['xc(0)', 'yc(0)', 'zc(0)']:
+                continue
+            oriented_curve.set(dname, xyzcurve.get(dname))
+
+        oriented_curve.set('x0', xyzcurve.get('xc(0)'))
+        oriented_curve.set('y0', xyzcurve.get('yc(0)'))
+        oriented_curve.set('z0', xyzcurve.get('zc(0)'))
+
+        return oriented_curve