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guillaumetousignant / NDG_cuda

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Chebyshev polynomials don't work. #2

Open guillaumetousignant opened 3 years ago

guillaumetousignant commented 3 years ago

Chebyshev polynomials should be drop-in replaceable with Legendre ones. Right now it doesn't work, the curves go crazy pretty quick.

guillaumetousignant commented 3 years ago

Seems to work with -D instead of D_hat (WHY??) and no fluxes for a while. There is a disparity at boundaries because there should be fluxes.

guillaumetousignant commented 3 years ago

Maybe has something to do with the fact that a function should be multiplied by 1/sqrt(1 - x^2) when integrating?

guillaumetousignant commented 3 years ago

Maybe the derivative matrix is not correct?

guillaumetousignant commented 2 years ago

Textbook p. 31 maybe has something, it's describing the coefficient for Chebyshev derivatives.