# Matlab: Simulation of Random Walk

I want to simulate a random walk in Matlab: I've found this code but it doesn't work. I have an error with the function S.simByEuler. Someone can explain me how to solve the error?

N = 60
F = @(t,X)  zeros(N,1);  %drift
G = @(t,X) eye(N); %diffusion
S = sde(F,G,'startState', discount_asset_price(1:60)');

M = 10
simulated_set = S.simByEuler(M,'nTrials',1,'Z',@(t,X)
RandDir(N));


where discount_asset_price is the data.

Matlab gives this error: Random variate function Z(t,X(t)) is invalid.

• What is the error? – Bob Jansen Aug 14 '20 at 16:59
• Matlab gives this error: Random variate function Z(t,X(t)) is invalid. – user48282 Aug 14 '20 at 17:08