Question

用下面代码建了一个function文件 function f=Language(x,y,x0) syms t; if(l

Answer 1

function [f,f0]=Language(x,y,x0)%%你要输出f和f0,那你的函数的输出参数个数必须是2个

syms t;

if(length(x)==length(y))%%这里是判断,不能用=,要用==

n=length(x);

else

disp('x和y的维数不相等');

return;

end

f=0.0;

for(i=1:n)

l=y(i);

for(j=1:i-1)

l=l*(t-x(j))/(x(i)-x(j));

end;

for(j=i+1:n)

l=l*(t-x(j))/(x(i)-x(j));

end;

f=f+l;

simplify(f);

end

f0=subs(f,'t',x0);

%%其它的不用改

>> x=0:0.5:3;

y=[ 0 0.4794 0.8415 0.9975 0.9093 0.5985 0.1411];

[f,f0]=Language(x,y,1.6)

f =

-799/3125*t*(t-1)*(t-3/2)*(t-2)*(t-5/2)*(t-3)+561/500*t*(t-1/2)*(t-3/2)*(t-2)*(t-5/2)*(t-3)-133/75*t*(t-1/2)*(t-1)*(t-2)*(t-5/2)*(t-3)+3031/2500*t*(t-1/2)*(t-1)*(t-3/2)*(t-5/2)*(t-3)-399/1250*t*(t-1/2)*(t-1)*(t-3/2)*(t-2)*(t-3)+1411/112500*t*(t-1/2)*(t-1)*(t-3/2)*(t-2)*(t-5/2)

f0 = 0.9996

%%%直接调用运行,上面是运行结果.