Why my plot is not working?

I have a problem with my plot. When I do plot(R). This picture will be shown

and when I do plot(y), this picture will be shown

I hope, when I do plot(y,R), this picture will be shown

but. When I try do plot(y,R). The picture show different like this

How to fix it?

This is my code

clc;
clear all;
T=readtable('polinom.xlsx');
xa=T.x;
ya=T.y;
x=transpose(xa);
y=transpose(ya);
n =length(x);
my=sum(y);
m = sum(bsxfun(@power,x(:),1:(2*n)),1);
myy = sum(bsxfun(@power,y(:),1:(2*n)),1);
xv = x(1:n);
yv = y(1:n);
ny = sum(bsxfun(@times,bsxfun(@power,xv(:),1:99),yv(:)),1);


for na=2:83
for i=1:na
    for j=1:na
        for k=1:na
        A(1,1)=n;
        if i>1
        A(i,1)=m(i-1);
        end
            if k>1 
                A(i,k)=m(k-1);
            if A(i,k)==A(i,k-1) 
                A(i,k)=m(k);
            elseif A(i,k)<A(i,k-1)
                    A(i,k)=m(i+k-2);
            end
        end
       
    end
    end
end
B=[my 1];
for i=2:na
    b = ny(i-1);
    B(i)=b;
end

for k=1:na-1
    for i=k+1:na
        if A(i,k)~=0
            lambda=A(i,k)/A(k,k);
            for j=1:na
                A(i,j)=A(i,j)-lambda*A(k,j);
            end
            B(i)=B(i)-lambda*B(k);
        end
    end
end


for i=na:-1:1
    sum=0;
    X(i)=0;
    for j=1:na
        sum=sum+A(i,j)*X(j);
    end
    X(i)=(B(i)-sum)/A(i,i);
end
for c = 1:n
    R(c) = 0;
    for d = 1:na
        R(c) = R(c)+X(d)*x(c)^(d-1);
    end
end
na;
R;
error=abs(y-R);

t=0;
for s = 1:length(error)
    t= t + error(s);
end
t;
ta(na)=t;

end
ta(1)=300;
ta;

xc=min(ta);
find(xc);
figure(100)
plot(y,R)

Answer 1

[Sriram Tadavarty]

Hi Eddy,

To get the desired plot, you can perform the following

% Option 1: To use it with the appropriate indexing
plot(1:length(y),y,1:length(R),R)

% Option 2: To use the hold on
plot(y)
hold on
plot(R)

The issue with using plot(y,R) is that it takes the first argument as x-axis and is R is plotted as a function of y. But, that is not what you are looking for.

Hope this helps.

Regards,

Sriram

[Eddy Iswardi]

thank you very much