Matlab之用牛顿均差求插值多项式

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% page 151  3
% 写出一个插值多项式
% input :vector(x,y),interpolation point x0
% output:the result at x = x0
, p. y4 J; X, u& v, O, ifunction y0 = page_157_1(x ,y,x0)
( F6 W% A/ x" kformat long
n = length(x);
9 u( h* W1 K& _* C( i% [/ tfor j = 1:n     %fill in y colum of Newton triangle
    v(j,1) = y(j);
6 D- c! v( ~4 ]end
for i = 2:n             %for colum i
    for j = 1:n+1-i             %fill in colum from top to bottom
        v(j,i) = (v(j+1,i-1) - v(j,i-1))/(x(j+i-1)-x(j));
    end
+ r) r) t+ |" a6 z% C$ Dend
for i = 1:n
- m8 T3 O- a- l* h# d0 @# [5 P    v(i) = v(1,i);     %read along top of triangle      
end     %output coefficients
y0 = v(n)*(x0 - x(n-1)) + v(n-1);  %initial nest
for i = 1:n-2                          %use nest
" g/ K+ I8 x" R7 b) L( ^    y0 = y0*(x0 - x(n-1-i)) + v(n-1-i);
0 t$ f& C# _# A7 }9 j9 bend

youOK

Matlab之用牛顿均差求插值多项式