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44 lines
633 B
44 lines
633 B
function [N] = NURBS_1D(xi, i, p,n, Xi,w)
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N = zeros(size(w));
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for j = 1:n
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N(j) = deBoor(xi,j,p,Xi);
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end
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R = N(i)*w(i)/sum(N.*w);
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N= R;
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return
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function [N] = deBoor(xi, i, p, Xi)
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if p==0
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if xi==Xi(i) && xi==Xi(i+1)
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N = 0;
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elseif xi>=Xi(i) && xi<=Xi(i+1)
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N = 1;
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else
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N = 0;
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end
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else
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if Xi(i) ==Xi(i+p)
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f = 0;
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else
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f = (xi - Xi(i))/(Xi(i+p)-Xi(i));
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end
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if Xi(i+1) == Xi(i+p+1)
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g = 0;
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else
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g = (Xi(i+p+1)-xi)/(Xi(i+p+1)-Xi(i+1));
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end
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N = f*deBoor(xi,i,p-1,Xi) + g*deBoor(xi,i+1,p-1,Xi);
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end
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return
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