Marco Sulla writes: > Another big problem with tensors is the covariance and contravariance. > Usually in informatic you denote the covariance with the subscript > operator, that on paper is written as subscript. Contravariant index > on the contrary is a superscript.
You're talking about the notation that makes the Einstein summation convention so pleasant? I think summation will have to be an explict operator or function, along a specified axis -- as numpy supports. > Not sure how a programming language can easily represent it. Do you need to represent it? It seems to me you could have a Tensor class whose constructor takes a bool argument 'contravariant' (default False), and then recommend that users adopt a naming convention to distinguish covariant Tensors from contravariant Tensors. Steve _______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-le...@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/QSLTWFNKN2K4WGKX44WXXQMP4CFOD6XY/ Code of Conduct: http://python.org/psf/codeofconduct/
