Syntax error to generate Log Normal Variables

I would like to generate 2x4 matrix of values which are log normally distributed

with mu= 1.175 and sigma = 0.0768 .. However when I write the following command

A= lognrnd(1.175,0.0768,2,4);

It appears the ouput error as follows:

??? Undefined function or method 'lognrnd' for input arguments of type 'double'.

Can any person please help me to resolve the issue ?

[Star Strider]

It is a Statistics Toolbox function.

Type:

which lognrnd -all

on the Command Line to see if it exists on your system, and to be sure there is only one function with that name.

[Jav Neo]

Thanks Star ... I have checked and it says that I dont have licence avaliable ...

Is there Any alternate way to generate log normal random values???

Answer 1

[Matt Fig]

Use this instead:

A = exp(randn(2,4).*0.0768+1.175)

Or make a little function:

Lognrand = @(S,mu,sig) exp(randn(S).*sig+mu);
A = Lognrand([2,4],1.175,0.0768);

To check:

m = 5/3;
v = 7/5;
mu = log((m^2)/sqrt(v+m^2));
sigma = sqrt(log(v/(m^2)+1));
A = Lognrand([1,1e7],mu,sigma);
abs(mean(A)-m)/m  % Should be pretty small
abs(var(A)-v)/v

[Jav Neo]

What S stand here ??

[Matt Fig]

Like I show, S is the size. So S=[2,4] means you will get a 2-by-4 array.