Subscript indices must either be real positive integers or logicals

Hi all,

I'm trying to do the following:

% simulate a Poisson process with rate \lambda = 3/2
lambda = 3/2;
% MATLAB function poissrnd uses the waiting time method
random_sample = poissrnd(lambda, 1, 4000)

% estimate the distribution
p = poisscdf(random_sample, lambda)

% plot the distribution
x = min(random_sample):1:max(random_sample)
y = double(poisscdf(x, lambda))
z = x+1
plot(z,y)

but I keep getting this error message. Does anyone know what could the problem be?

Thanks a lot!

Please post a copy of the error message, which reveals e.g. the line, which causes the error.

Actually, it worked well after I tried to run it again. Thanks for your time!

Answer 1

I can guess only at the moment, that one of the commands has been defined as variable before, e.g. poissrnd, poisscdf, min, max, double or plot. The standard procedure to locate the problem is using the debugger:

dbstop if error

Then run your program again until Matlab stops in the line, which causes the error. Now let which min -all or whatever commands are used in the line show you the definition of the symbols. In general, avoid to use names of built-in functions as names of variables, because this causes problems frequently.