error message

Hi,
I tried to run a Matlab code with Octave and it returned with following error message. 
error: 'rate_eq' undefined near line 10 column 25error: called from    laser_rate_equation>@<anonymous> at line 10 column 25    starting_stepsize at line 46 column 5    ode45 at line 192 column 25    laser_rate_equation at line 10 column 10
It seems Octave doesn't accept this command [T,Y]= ode45(@(t,y) rate_eq(t,y,V),tspan,y0); this is exactly the same way to call function with both Matlab and Octave.
How do I fix the problem?
Best Regards,Tso-Min
ps; The function rate_eq is
function dy= rate_eq(t,y,V)dy = zeros(3,1);I = 0.3;te = 2.2E-9;tp = 1.6E-12;BuyukGama = 0.3;a = 2.5E-20;Betasp=10^-3;B=10E-16;c=3*10^8;e = 1.602E-19;ug=4;n0 = 1E24;h = 6.626074E-34;vg= c/ug;am=45E2;nuu =(c/1300E-9);dy(1) = (I/e) - y(1)/te - (BuyukGama*c*a*(y(1)/V-n0)/ug)*y(2);dy(2) = (BuyukGama*c*a*(y(1)/V-n0)/ug)*y(2)- y(2)/tp + Betasp*B*y(1)^2/V ;dy(3) = h*nuu*vg*am*dy(2)/2;end


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