How can I plot a function with parametric if (change between parameters)

I have the function :

 t(r) = 39.64                         if 0<r<r0 and 
 t(r) = 51.4875* exp( 0.14*(16.37-r)) if r0<r

where r in R(real numbers) and

 r0 = 12.5

How I can get the plot/graph of function t(r) ...? Thanks! (Maybe the title question doesn't fit well in the meaning)

Answer 1

[Mischa Kim]

Chris, this should do the trick

 r  = 0:0.1:20;
 r0 = 12.5;
 t  = 39.64*(r<=r0) + 51.4875*exp(0.14*(16.37 - r)).*(r>r0);

 plot(r,t)