add ArrayFunc.tangent

evalf · Mar 4, 2015 · 1af3db3 · 1af3db3
1 parent 9cd416f
commit 1af3db3
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/nutils/function.py b/nutils/function.py
@@ -559,6 +559,10 @@ def dotnorm( self, coords, ndims=0, axis=-1 ):
     assert normal.shape == (self.shape[axis],)
     return ( self * normal[(slice(None),)+(_,)*(self.ndim-axis-1)] ).sum( axis )
 
+  def tangent( self, geom ):
+    normal = geom.normal()
+    return self - ( self * normal ).sum(-1)[...,_] * normal
+
   def ngrad( self, coords, ndims=0 ):
     'normal gradient'