How do I get the plot for this code?

I have used the trapetzoid rule. How do I get the plot for this code?

 function T = time_to_destination(x,route, n)

 load(route);

   if x<0||x>distance_km(end) 

   error("Too big/small")

   end

 h=x/n;

 j=1./(velocity(linspace(0,x,n+1), route));

 T=0.5*h*(2*sum(j)-j(1)-j(end))

 end

.

 function v = velocity(x, route)

load speed_anna.mat;

d = distance_km;
y = speed_kmph;
dd=0:distance_km(end);

pp=spline(d,y); 
v = ppval(pp, x);

plot(d,y,'ro'); 

    hold on
    h=fplot(@(x)ppval(pp,x),[d(1),d(end)], '- b')
    hold off

 if (x<0 | x>d(end))
    error ('Fel')
 end
 end

Answer 1

[Rava Sash]

I meant trapezoidal rule* Can't anyone help me? Do I need to convert the vectors to a matrix? If so, how do I do that?

[Walter Roberson]

Your code is pretty odd but it appears to already be plotting, so I do not understand the question.

Sample input would help.

[Rava Sash]

I don't know why I put both the codes in, but I only want to plot the first function. Sorry for the confusion.

Answer 2

[Walter Roberson]

It is difficult to guess what you want. Perhaps

 function T = time_to_destination(x,route, n)

 load(route);

   if x<0||x>distance_km(end) 

   error("Too big/small")

   end

 h=x/n;

 X = linspace(0,x,n+1);
 j=1./(velocity(X, route));

 T=0.5*h*(2*sum(j)-j(1)-j(end));

 plot(X, j)