Please Help! : Unrecognized function or variable 'crandn'.

% simple SIMO system

m = 2;
l = 20;
alphabet = [ exp(j*pi/4); exp(j*3/4*pi); exp(j*5/4*pi); exp(j*7/4*pi) ];

h0 = crandn(m, 1);
h1 = crandn(l, 1);
h2 = crandn(m, l);
hmatrix1 = diag(h1);

ptx = 1;

vinit = alphabet(round(4*rand(l, 1)+0.5));
htotinit = (h0+h2*diag(vinit)*h1)*sqrt(ptx);
ginit = htotinit/(1+htotinit'*htotinit);
mseinit = 1/(1+htotinit'*htotinit);

gold = ginit;
vold = vinit;
mseold = mseinit;
iter = 1;
while 1 == 1,
	a = hmatrix1'*h2'*gold;
	b = gold'*h0-1;
	vcand = b/abs(b)*a./abs(a);
	vnew = zeros(l, 1);
	vnew = sqrt(2)*((real(vnew) > 0)-0.5+j*(imag(vnew) > 0)-0.5);
	if round(norm(vnew-vold)) == 0,
	  break;
	end
	htotnew = (h0+h2*diag(vnew)*h1)*sqrt(ptx);
	gold = 1/(1+htotnew'*htotnew)*htotnew;
	mseold = 1/(1+htotnew'*htotnew);
    msenew = mseold
	vold = vnew;
	iter = iter+1;
end

msenew = 0.0055

disp(sprintf("MSEinit=%f", mseinit))

MSEinit=0.011244

disp(sprintf("MSEupdated=%f", msenew))

MSEupdated=0.005515

disp(sprintf("number of iterations=%i", iter))

number of iterations=2

Why is my matlab showing this error?

I am able to run my code here but not in my matlab program.

Can anyone help?

Answer 1

[Walter Roberson]

https://www.mathworks.com/matlabcentral/fileexchange/21325-crandn

[Alvin Ang]

Qn: Why am I unable to run my code in my program but I am able to run my code here?

[Image Analyst]

which crand

/MATLAB/toolbox/robust/rctutil/crand.m

Do you have that toolbox? What toolboxes are listed when you do "ver"?

[Alvin Ang]

Oh I understand now, i have to install the toolbox. Thank you.

[Walter Roberson]

oh I missed that one, it isn't documented! https://www.mathworks.com/matlabcentral/answers/495798-why-can-t-i-use-crand-in-matlab#answer_405656