helixish: railway_inplane_basis should not include a scale factor

Err, maybe it should ?

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

diff --git a/helixish.py b/helixish.py
index 1d36faecef8e4b55501b8384259b589cced9e980..e49ed120045eba6efe6892cc2033d1943e938c90 100644 (file)
--- a/helixish.py
+++ b/helixish.py
@@ -89,7 +89,7 @@ class HelixishCurve():
     railway_cos_theta = cos(railway_theta)
     railway_cos_phi   = cos(railway_phi)
 
-    railway_inplane_basis_x = np.hstack((q_plane[0:2], [0]))
+    railway_inplane_basis_x = unit_v(np.hstack((q_plane[0:2], [0])))
     railway_inplane_basis = np.column_stack((
       railway_inplane_basis_x,
       np.cross([0,0,1], railway_inplane_basis_x),