How to use sparse matrix without any problem with MAXSIZE ?

I want to use mRMR algorithm and a part of code is using mutualinfoDis function that it's code is:

% feature-selection-mRMR
% Created by Jiahong K. Chen

% Input: x, y two vector of discrete data
% Output: I(x,y) = mutual information of x and y

function mi = mutualInfoDis(x, y)

 n       = length(x);

% reshape x and y into column vector
x       = x(:);
y       = y(:);

% shift x and y to 1:max([x;y])
lo      = min( [ x; y ] );
x       = x - lo + 1;
y       = y - lo + 1;
up      = max( [ x; y ] );

% negative Joint entropy
idx     = (1:n);
tabX    = sparse(idx, x, 1, n, up, n);
tabY    = sparse(idx, y, 1, n, up, n);
Pxy     = nonzeros(tabX'*tabY) / n;
negHxy  = Pxy' * log(Pxy);

% negative Entropy
Px      = mean(tabX);
Py      = mean(tabY);
negHx   = Px * log(Px)';
negHy   = Py * log(Py)';

% Mutual information
mi      = negHxy - negHx - negHy;
%mi      = mi/log(2);

end

but this error is showed:

Error using sparse
Sparse matrix sizes must be non-negative integers less than MAXSIZE as defined by COMPUTER.  Use HELP COMPUTER for more
details.

Error in mutualInfoDis (line 23)
tabX    = sparse(idx, x, 1, n, up, n);

I obtained the maxsize of the MATLAB program installed on my computer that is

>> [str,maxsize]=computer

str =

PCWIN64


maxsize =

   2.8147e+14

But I don't know how to solve this error,I changes n to this value or less than maxsize but still, the program has problem with using sparse, I'll be vary grateful to have your opinions.Thank You

[Matt J]

What is the value of "up"?

[Steven Lord]

The values of n and up would be useful to know to determine if what you're trying to do is possible.

[phdcomputer Eng]

@Matt J up is obtained 1.4876e+04

[phdcomputer Eng]

@Steven Lord n=62 and up=1.4876e+04 how to solve the error of these lines

tabX = sparse(idx, x, 1, n, up);

tabY = sparse(idx, y, 1, n, up);