From adaeb0e1eff41199e11c079af0c0b092e4f08c37 Mon Sep 17 00:00:00 2001
From: Claudio	Zambaldi <c.zambaldi@mpie.de>
Date: Mon, 3 May 2010 18:27:19 +0000
Subject: [PATCH] rotation axis is undefined for small angles and therefore
 gets a NaN

---
 code/math.f90 | 1 +
 1 file changed, 1 insertion(+)

diff --git a/code/math.f90 b/code/math.f90
index e826cdecd..502f02cdc 100644
--- a/code/math.f90
+++ b/code/math.f90
@@ -1391,6 +1391,7 @@ pure function math_transpose3x3(A)
  
  if (sinHalfAngle <= 1.0e-4_pReal) then             ! very small rotation angle?
    math_QuaternionToAxisAngle = 0.0_pReal
+   math_QuaternionToAxisAngle(1:3) = NaN
  else
    math_QuaternionToAxisAngle(1:3) = Q(2:4)/sinHalfAngle
    math_QuaternionToAxisAngle(4) = halfAngle*2.0_pReal*inDeg