i try to do quadratic interpolation with 3 initial guesses. when i run the code it do nothing
d=input(‘Please enter a function f(x): ‘);
x0=input(‘Please give a initial guess of x0: ‘);
x1=input(‘Please give a initial guess of x1: ‘);
x2=input(‘Please give a initial guess of x2: ‘);
signum=input(‘Please enter the prespecified error: ‘);
f=inline(d);
i=1;
x3=(f(x0)*(x1^2-x2^2)+f(x1)*(x2^2-x0^2)+f(x2)*(x0^2-x1^2))/(2*f(x0)*(x1-x2)+2*f(x1)*(x2-x0)+2*f(x2)*(x0-x1));
x(i)=x3;
error(i)=9999;
es=(0.5*10^(2-signum));
while error(i)>=es
x(i+1)=(f(x0)*(x1^2-x2^2)+f(x1)*(x2^2-x0^2)+f(x2)*(x0^2-x1^2))/(2*f(x0)*(x1-x2)+2*f(x1)*(x2-x0)+2*f(x2)*(x0-x1));
a=x(i+1);
if f(a)>f(x0)
if f(a)>f(x2)
x0=x1;
x1=x(i+1);
x(i+1)=(f(x0)*(x1^2-x2^2)+f(x1)*(x2^2-x0^2)+f(x2)*(x0^2-x1^2))/(2*f(x0)*(x1-x2)+2*f(x1)*(x2-x0)+2*f(x2)*(x0-x1));
elseif f(a)<f(x2)
x2=x1;
x1=x(i+1);
end
end
error(i+1)=abs((((x(i+1)-x(i))/(x(i+1)))*100));
i=i+1;
endd=input(‘Please enter a function f(x): ‘);
x0=input(‘Please give a initial guess of x0: ‘);
x1=input(‘Please give a initial guess of x1: ‘);
x2=input(‘Please give a initial guess of x2: ‘);
signum=input(‘Please enter the prespecified error: ‘);
f=inline(d);
i=1;
x3=(f(x0)*(x1^2-x2^2)+f(x1)*(x2^2-x0^2)+f(x2)*(x0^2-x1^2))/(2*f(x0)*(x1-x2)+2*f(x1)*(x2-x0)+2*f(x2)*(x0-x1));
x(i)=x3;
error(i)=9999;
es=(0.5*10^(2-signum));
while error(i)>=es
x(i+1)=(f(x0)*(x1^2-x2^2)+f(x1)*(x2^2-x0^2)+f(x2)*(x0^2-x1^2))/(2*f(x0)*(x1-x2)+2*f(x1)*(x2-x0)+2*f(x2)*(x0-x1));
a=x(i+1);
if f(a)>f(x0)
if f(a)>f(x2)
x0=x1;
x1=x(i+1);
x(i+1)=(f(x0)*(x1^2-x2^2)+f(x1)*(x2^2-x0^2)+f(x2)*(x0^2-x1^2))/(2*f(x0)*(x1-x2)+2*f(x1)*(x2-x0)+2*f(x2)*(x0-x1));
elseif f(a)<f(x2)
x2=x1;
x1=x(i+1);
end
end
error(i+1)=abs((((x(i+1)-x(i))/(x(i+1)))*100));
i=i+1;
end d=input(‘Please enter a function f(x): ‘);
x0=input(‘Please give a initial guess of x0: ‘);
x1=input(‘Please give a initial guess of x1: ‘);
x2=input(‘Please give a initial guess of x2: ‘);
signum=input(‘Please enter the prespecified error: ‘);
f=inline(d);
i=1;
x3=(f(x0)*(x1^2-x2^2)+f(x1)*(x2^2-x0^2)+f(x2)*(x0^2-x1^2))/(2*f(x0)*(x1-x2)+2*f(x1)*(x2-x0)+2*f(x2)*(x0-x1));
x(i)=x3;
error(i)=9999;
es=(0.5*10^(2-signum));
while error(i)>=es
x(i+1)=(f(x0)*(x1^2-x2^2)+f(x1)*(x2^2-x0^2)+f(x2)*(x0^2-x1^2))/(2*f(x0)*(x1-x2)+2*f(x1)*(x2-x0)+2*f(x2)*(x0-x1));
a=x(i+1);
if f(a)>f(x0)
if f(a)>f(x2)
x0=x1;
x1=x(i+1);
x(i+1)=(f(x0)*(x1^2-x2^2)+f(x1)*(x2^2-x0^2)+f(x2)*(x0^2-x1^2))/(2*f(x0)*(x1-x2)+2*f(x1)*(x2-x0)+2*f(x2)*(x0-x1));
elseif f(a)<f(x2)
x2=x1;
x1=x(i+1);
end
end
error(i+1)=abs((((x(i+1)-x(i))/(x(i+1)))*100));
i=i+1;
end quadratic polynomial interpolation curve fitting MATLAB Answers — New Questions
