User Portlet
| Discussions |
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| Thank you for your suggestion! |
| As far as I understand, these lines work like this: 1. `NN` is an integer variable defined somewhere above; 2. `idx` is expected to be a list of integers not exceding `NN` so that `Complement[Range[NN], idx]` returns a non-empty list of indices... |
| Hello! As I understand, this is WL notation for "everywhere else" / "where not specified". For example, one can use it in boundary conditions of PDEs, e.g., `NeumannValue[0, True]`, which means something like "zero flux everywhere on the boundary". |
| Thank you all for your replies! Yes, my question arose exactly from Python - my colleague works on the ANN-based [eikonal equation][1] solver implemented with Tensorflow - and I wanted to play with this problem using WL. A particular thanks to... |
| You are totally right, Neil. This is a bug. I tried Properties, Options, Information before my post and searched on the net. None of them gives something helpful. I think I once reported a bug, but don't remember how to do this. Can you tell me? |
| You can do a lot this way: sol = NDSolveValue[{D[r[t], t] == (r[t].r[t])^-1 RotationMatrix[Pi/2, {0, 0, 1}].r[t], r[0] == {1, 1, 1}}, r, {t, 0, 1}] sol[1] |
| Bill, Thank you, an interesting idea, though I am not too sure how to interpret the output in relation to my problem. |
| Hi Nikolay, That looks like a bug. Existing values are overwritten. It is as if symbols scoped using `Block` are not being restored to their value in the outer scope. You should report it to Wolfram Support. You can use `Remove[x, y, z]` to... |
| UPD: I re-installed Mathematica and it fixed the problem. Maybe the cause was that I installed CUDA Toolkit *after* the previous Mathematica installation downloaded GPU libraries and threw an error. |
| Thanks for your replies! |