plot when a value of zero makes issue

my code below is supposed to plot different graph with different value of t:

many thanks

c=2;
nu = 1*1e-6;
    r = linspace(0,100);
    t=[1/2 1 2 6 10 20 50 ];
for count=1:7
    v = c * (1-exp(-r.^2./(4*nu*t(count))))./r;
    plot(r,v,'o-')
    legend([' t= ',num2str(t(count))])
    legend show
    ylabel('v(m/sec)')
    xlabel('r(m)')
    grid on
    hold on
end

Answer 1

[David Hill]

If you change your nu to something more reasonable, it provides the graphs dynamics you are looking for.

nu=10;

[David Hill]

c=2;
nu = 10;
r = linspace(0,100);
t=[1/2 1 2 6 10 20 50 ];
hold on;
for count=1:7
    v = c * (1-exp(-r.^2./(4*nu*t(count))))./r;
    plot(r,v,'o-');
end
legend([' t= ',num2str(t(1))],[' t= ',num2str(t(2))],[' t= ',num2str(t(3))],[' t= ',num2str(t(4))],[' t= ',num2str(t(5))],[' t= ',num2str(t(6))],[' t= ',num2str(t(7))]);
legend show;
ylabel('v(m/sec)');
xlabel('r(m)');
grid on;

[H-M]

Thank you so much David for your help.It works perfect.

would you please explain why hold on shoul be before the loop?

[David Hill]

No reason to execute hold commend multiple times in the loop. Once is enough.

[H-M]

Thank you so much David