www.pudn.com > NumericalComputingwithMatlabCode.zip > vandal.m, change:2003-11-30,size:529b

function d = vandal(n) % VANDAL Symbolic Vandermonde matrix. % Exercise: % What does VANDAL(N) compute and how does it compute it? % Under what conditions on X is the matrix VANDER(X) nonsingular? x = sym(ones(n,1)); for i = 1:n x(i) = sym(['x' int2str(i)]); end V = sym(ones(n,n)); for j = 2:n V(:,j) = x.*V(:,j-1); end pretty(V) d = 1; for k = 1:n-1 for i = k+1:n V(i,:) = V(i,:) - V(k,:); p = V(i,k+1); d = d*p; V(i,:) = simplify(V(i,:)/p); end end