How to select one number from a loop. I want to calculate the time t when m5=99.9. when I run the program it doesn't show anything. I don't know how to print t from the time loop when m5=99.99

dt = 0.01;       % Step size
tend = 50;       % End time
t = 0:dt:tend;   % Time vector
%Loop for m5 calculation
for i=1:(length(t)-1) 
     for j=1:length(i) 
         k1 = f5(t(i),m5(i)); 
         k2 = f5(t(i)+0.5*dt,m5(i)+0.5*dt*k1); 
         k3 = f5((t(i)+0.5*dt),(m5(i)+0.5*dt*k2)); 
         k4 = f5((t(i)+dt),(m5(i)+k3*dt)); 
     end
         m5(i+1) = m5(i) + (1/6)*(k1(j)+2*k2(j)+2*k3(j)+k4(j)).*dt;
         if m5==99.9
             break
                fprintf('%d',t(i))
            end

Answer 1

[the cyclist]

The reason you don't an exact match has to do with the representation of floating point numbers.

Instead of testing with

if m5==99.9

try

tol = 1.e-5;
if abs(m5-99.9) < tol