The example SM_sphere_S2 breaks when it gets to section 'Tangent Spaces', thus:
AttributeError: 'DifferentiableManifold_with_category' object has no attribute 'tangent_space'.
referring to the manifold S2.
Why would a differentiable manifold not have a tangent space? or does the example need to be modified?
This is because SageManifolds is not fully integrated in SageMath 7.3. Only the part corresponding to the tickets #15916 to #18783 in the list https://trac.sagemath.org/ticket/18528 is there. As you can see, tangent spaces (ticket #19092) are not in SageMath yet. Hopefully, it will be in version 7.4. Meanwhile, simply install the full SageManifolds atop SageMath 7.3 by following these instructions and all the S^2 examples should pass.
@Richard_L, you can accept (by clicking the tick mark) and upvote (by clicking the up arrow) erig_g's answer, so that your question is marked in the list of Ask Sage questions as solved.
Asked: 2016-08-12 19:39:13 +0200
Seen: 273 times
Last updated: Aug 13 '16
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