3 d plot for the symbolic calculation

syms x a t

f=1

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

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

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

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

U(1)=(r-1)/((1+exp(x))^2);

for k=1:2

A(1)=0;

for i=1:k

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

end

U(k+1)=simplify(gamma((f*(k-1)+1))/gamma((f*(k)+1))*(diff(U(k),x,2)+6*U(k)-6*A(1)));

end

disp (U)

for k=1:2

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

end

series

row=0;

x=0.7;

series1(r,t)=series(0.7,t)

for r=1:5

row=row+1;

col=0;

e=(r)/10;

for t=1:5

col=col+1;

f=(t);

C(row,col)=series1(e,f);

end

end

t= vpa(C,15)

fsurf(series1,[0.1 0.1 0.5],[1 1 5])

what is correct syntax to plot 3D command ? fsurf(series1,[0.1 0.1 0.5],[1 1 5]) is showing error.

Answer 1

[Star Strider]

The problem was with the fsurf call (and ‘r’ was not defined).

This changed version:

fsurf(series1,[-50 50 0 50])

works —

syms x  a  t  r 
f=1

f = 1

U=zeros(1,2,'sym');
A=zeros(1,2,'sym');
B=zeros(1,2,'sym');
series(x,t)=sym(zeros(1,1));
U(1)=(r-1)/((1+exp(x))^2);
for k=1:2
    A(1)=0;
        for i=1:k
        A(1)=A(1)+U(i)*U(k-i+1) ;
        end
      U(k+1)=simplify(gamma((f*(k-1)+1))/gamma((f*(k)+1))*(diff(U(k),x,2)+6*U(k)-6*A(1)));
end
 disp (U)

  for k=1:2
      series(x,t)=series(x,t)+U(k)*(power(t,k-1));
  end
   series

series(x, t) = 

  row=0;
 x=0.7;
 series1(r,t)=series(0.7,t)

series1(r, t) = 

 for r=1:5
     row=row+1;
     col=0;
     e=(r)/10;
     for t=1:5
         col=col+1;
          f=(t);
           C(row,col)=series1(e,f);
    end   
 end
t= vpa(C,15)

t = 

fsurf(series1,[-50 50  0 50])
xlabel('r')
ylabel('t')
colormap(turbo)
view(120, 30)

.