problem with f surf

f1 = @(x,t) 0.7*(1-tanh((0.7/2)*((x)-0.7*(t))))

syms x n

syms t

U=zeros(1,2,'sym');

A=zeros(1,2,'sym');

B=zeros(1,2,'sym');

series(x,t)=sym(zeros(1,1));

U(1)=0.7*(1-tanh((0.7/2)*x))

for k=1:3

A(1)=0;

for i=1:k

A(1)=A(1)+U(i)*U(k-i+1) ;

end

B(1)=0;

U(k+1)=(((diff(U(k),x,2)-A(1)))/k);

end

disp (U)

for k=1:4

series(x,t)=simplify(series(x,t)+U(k)*(power(t,k-1)));

end

% f2=series

f3=@(x,t) series

fsurf(f1,[-5 0 -5 5])

fsurf(f3,[-5 0 -5 5])

fsurf(f1-f3,[-5 0 -5 5])

The graph is not displayed

Answer 1

[Sulaymon Eshkabilov]

THere are a few errs in your code - loop calculations and redefining 'f3'. Here is the corrected code:

...
series=0;
for k=1:4
series=series+(U(k).*(power(t,k-1)));
end 
 f3= series;
 figure(1)
 fsurf(f1,[-5 0 -5 5])
 figure(2)
 fsurf(f3,[-5 0 -5 5])
 figure(3)
fsurf(f1-f3,[-5 0 -5 5])

[yogeshwari patel]

Thank you

[Sulaymon Eshkabilov]

Most Welcome!