Attempt to fix #5

src/PoseComposition.jl

@@ -294,8 +294,14 @@ interp(a::Pose, b::Pose, t::Real) = a * interp(a ⦸ b, t)
 
 function quatPow(q::UnitQuaternion, t::Real)
   # TODO: Once https://github.com/JuliaGeometry/Rotations.jl/issues/126 is
-  # fixed, this special case won't be necessary
-  if t == 0 || q == one(UnitQuaternion) || q == -one(UnitQuaternion)
+  # fixed, this special case won't be necessary.
+  #
+  # For an example showing why we need an approximately-equal check rather than an exact equality check, see
+  # https://github.com/probcomp/PoseComposition.jl/issues/5
+  ε = 1e-30
+  if (isapprox(t, 0; atol=ε)
+      || isapprox(q, one(UnitQuaternion); atol=ε)
+      || isapprox(q, -one(UnitQuaternion); atol=ε))
     return one(UnitQuaternion)
   end
   return exp(t * log(q))