How to graph an equation with one independent variable?

I have the equation:

c=(M/(pi*4*D*t))*exp((-r^2)/(4*D*t));

All of the variables,(M,D and t) are defined above the equation and i want to graph this equation where C is the dependent variable and r is the independent variable. How do I go about doing this? Thanks

Answer 1

[John D'Errico]

Just use ezplot. Assume the other variables are defined in advance. Else how could you plot it if they are not?

M = ???
D = ???
t = ???

Cfun = @( r) (M/(pi*4*D*t))*exp((-r.^2)/(4*D*t));
ezplot(Cfun)

Note the use of r.^2, to allow ezplot to use vectorized calls to this function handle.

If you wish to specify the axis limits, ezplot allows you to do so in the second argument.

Answer 2

[dpb]

First rewrite the equation to be able to use vector inputs using the "dot operatiors"

c=(M/(pi*4*D*t))*exp((-r.^2)/(4*D*t));

then set a range of r and evaluate

r=linspace(rStart,rEnd);
c=(M/(pi*4*D*t))*exp((-r.^2)/(4*D*t));
plot(r,c)

Done.