Not spotting where/how index exceeds number of array elements
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Brian Taff
le 13 Déc 2019
Commenté : Brian Taff
le 21 Déc 2019
I'm trying to solve a Navier-Stokes setup in a cylindrical coordinate system and am bumping up against an array indexing challenge. Any help folks might be able to offer to straighten matters out would be most appreciated. I'm including my live editor content below.
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Vladimir Sovkov
le 14 Déc 2019
Is this what you want? Live script vesion is attached.
xmesh = linspace(0.01,0.05,5);
solinit = bvpinit(xmesh, @guess);
sol = bvp4c(@bvpfcn, @bcfcn, solinit);
plot(sol.x, sol.y, '-o')
function bound = bcfcn(ua,ub)
bound = [ua(1)-0.1, ub(1)];
end
function g = guess(r)
g = [1*(0.05-r)/(0.05-0.01), -1/(0.05-0.01)];
end
function dudr = bvpfcn(r,u)
dudr = [u(2), u(2)./r];
end
4 commentaires
Vladimir Sovkov
le 20 Déc 2019
Modifié(e) : Vladimir Sovkov
le 20 Déc 2019
No prob.
I do not understand why you replace your initial equation by . It seems to me that must have been with the "plus" sign, and, consequently, dudr = [u(2), u(2)./r] in the program, isn't it? Otherwise, you are solving the equation .
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