On Thu, Aug 13, 2020 at 09:33:46PM -0700, Guido van Rossum wrote: > That's food for thought. I have to admit that I have forgotten almost > everything about linear algebra that I was ever taught
In Australia, at least, secondary schools don't spend a lot of time teaching matrices for linear algebra. It is, at most, only a portion of the matrix course. The main use for matrices is for (basic) financial problems and networks/graphs. Here is the topic list from one of my students: - Matrix arithmetic - Applications of matrix arithmetic - Binary, permutation, communication and dominance matrices - Solving simultaneous linear equations - Transition matrices Very little of the course is the traditional 1980s style linear algebra that you (Guido) and I would have learned. Two examples of practical questions taught these days: (1) Five students compete against each other in judo. The dominance matrix D shows the winner of each bout ... Rank the students with a one-step dominance score. Calculate the two-step dominance matrix. Determine the matrix T = D + D**2 and use it to rank the players. (This is an example where the matrices are all integer values, starting with just zeroes and ones. Numerical precision doesn't come into it.) (2) A car insurance company finds that 22% of car drivers involved in an accident this year are also expected to be involved in a accident next year; 9% of drivers who are not involved in an accident are expected to be involved in an accident next year. If the company insures 80,000 drivers, how many of them are expected to be involved in an accident during the next five years? > What gives me hope though is that Steven has been thinking about this > somewhat seriously already, and given that he successfully chose what to > include or exclude for the statistics module, I trust him to know how much > to put into a Matrix class as well. Certainly I trust him to come up with a > reasonable strawman whose tires we can all kick. Thank you for the vote of confidence :-) > My own strawman would be to limit a Matrix to 2-dimensionality -- I believe > that even my college linear algebra introduction (for math majors!) didn't > touch upon higher dimensionality, and I doubt that what I learned in high > school about the topic went beyond 3x3 (it might not even have treated > non-square matrices). Totally agree -- matrices are by definition limited to two dimensional arrays, including the limiting case of 1xN or Nx1 row/column matrices (vectors). Tensors generalise matrices to an arbitrary number of dimensions, 3D and above. https://medium.com/@quantumsteinke/whats-the-difference-between-a-matrix-and-a-tensor-4505fbdc576c I have never studied tensors and wouldn't know where to even begin a tensor library :-) -- Steven _______________________________________________ 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/FCHSZ62K3AGA2DWUPJXLIFYAB4NOL4TW/ Code of Conduct: http://python.org/psf/codeofconduct/
