How to plot two functions by using looping values in the same graph using Matlab?

I try to plot two function on the same graph from looping but all I get are just dots on the graph. I want it to be a smooth line graph. So how can I connect the dots? Please help.. this is my coding:

r=@(t) -0.5*(t.^4)+4*(t.^3)-10*(t.^2)+8.5*t+1;
f=@(x) -2*(x.^3)+12*(x.^2)-20*x+8.5;   %Diff of r%
h=0.5;
x0=0;
y0=1;
l=0;
fprintf ('      x                 Ytrue              YEuler            True Error        Percent Relative Error\n')
fprintf ('_______________________________________________________________________________________________________________\n')
fprintf ('\n')
for j=0.0:+0.5:4.0;
 m=r(j); 
 yx=y0+h*l; 
 l=f(j);
 et=m-yx;
 er=((m-yx)/m)*100;
 y0=yx;
 fprintf ('    %5.4f             %4.4f              %4.4f             %4.4f            %12.4f\n', [j,m,yx,et,er]')
 plot(j,m,'-')
 hold on
 plot(j,yx,'-')
end

Answer 1

[Azzi Abdelmalek]

instead plot, use scatter function

scatter(j,m)

Or store all your values in one array called m with same size as j, and use outside the loop

plot(j,m)

[Farah Nabilah Samsudin]

I already try it but the graph still resulted in dots. Here the attachment..