a matlab question need help!! please!!!!

Write a Matlab ’s function newtinterp.m with input arguments (x,y,u), where (xi,yi), i =
1, . . . , n + 1, the interpolation data points and u = [u1, . . . , um] the vector containing the m points on which we want to evaluate the interpolating polynomial. This will compute the coefficients of the interpolating polynomial ai and will return the values zi = pn(ui), i = 1,2,...,m using the previous algorithms.
Finally, consider the function f(x) = sinx, x ∈ [0,2π], and a uniform partition of [0,2π] with 6 points xi, i = 1, . . . , 6. Using your function newtinterp.m compute the interpolating polynomial p5, that interpolates function f at the nodes xi, at 101 equi-distributed points zi ∈ [0,2π]. Verify your results and compare them with those obtained by using the Matlab ’s functions polyfit and polyval.

I have the code like this:

function [p] = newtinterp( x , y , u)

n=length(x)-1;
a=y;
for k=2:n+1
    for i=1:k-1
        a(k)=(a(k)-a(i))/(x(k)-x(i));
    end 
end

p=0*u;
for t= 1:length(u)
    s=a(end)
    for i = n:-1:1
        s= a(i)+(u(t)-x(i))*s
    end
    p(t)=s;
end

and I try to run :

x=linspace(o,2*p,6)
y=sin(x)
newtinterp( x , y , 5)

it does't work.

%
>> newtinterpt(x,y,5)
Undefined function 'newtinterpt' for input arguments of type 'double'. %

Anyone can help me please??

[Matt Kindig]

You mis-spelled your function in your call. It should be 'newtinterp', not 'newtinterpt'.

Answer 1

[Mar Wan]

Find the interpolating polynomial to the function f(x) = e −x cos(νπx) using matlab

for x=-0.67.x=0,x=0.67

and v=67

[Mar Wan]

could you plz answer this?

[Steven Lord]

This is not related to the original question. Please post it as a new question rather than trying to resurrect an old unrelated question.