How to solve normcdf function error

Hi,

I have the following error log:

Error using erf
Input must be real and full.

Error in normcdf (line 47)
p(k) = 0.5 * (1 + erf((x(k) - mu(k)) ./ (sigma(k) * sqrt(2))))_ _

the code used is:

function p = normcdf(x,mu,sigma)

if nargin < 3, 
    sigma = 1;
end

if nargin < 2;
    mu = 0;
end

[errorcode x mu sigma] = distchck(3,x,mu,sigma);

if errorcode > 0
    error('The arguments must be the same size or be scalars.');
end

p = zeros(size(x));

k1 = find(sigma <= 0);
if any(k1)
    p(k1) = NaN * ones(size(k1)); 
end

k = find(sigma > 0);
if any(k)
p(k) = 0.5 * (1 + erf((x(k) - mu(k)) ./ (sigma(k) * sqrt(2))));

end  

k2 = find(p > 1);
if any(k2)
    p(k2) = ones(size(k2));
end

Please could you help me to solve this issue? thanks a lot in advance Irene

[Geoff Hayes]

Irene - how are you calling the normcdf function? What inputs are you using? I noticed that you tagged your question with symbolicnumber. Are you passing a symbol into this function?