Question: How do I discretise the 4th order PDE?

Dear All.

Please kindly help to correct the attached code on discretization of fourth order PDE using method of line.
Thank you and kind regards.

restart

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Discretization of parabolic equation with method of line

diff(u(x, t), t) = -2*(diff(diff(u(x, t), x), x))-(diff(diff(diff(diff(u(x, t), x), x), x), x))-u(x, t)*(diff(u(x, t), x))

u(x, t)

u(x, t)

u(x, 0) = 0.3e-1*sin(x)

8

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Convert the BC to finite difference

(1/2)*(u[m+1](t)-u[m-1](t))/h

(u[m-1](t)-2*u[m](t)+u[m+1](t))/h^2

(u[m-2](t)-4*u[m-1](t)+6*u[m](t)-4*u[m+1](t)+u[m+2](t))/h^4

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Convert the governing equation to finite difference form

Error, invalid input: diff received 2*h, which is not valid for its 2nd argument

Error, invalid input: diff received 2*h, which is not valid for its 2nd argument

Error, invalid input: LinearAlgebra:-GenerateMatrix expects its 1st argument, eqns, to be of type ({list, set})({`=`, algebraic}), but received eqs

A

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