Simple ols function conducting an error stting tht the matrix is small however thisis what is only needed in the equation

whenever I compute a simple ols i receive this message and also another error stating (wrong number of arguments to ols). Accordingly what should i do ?

y = Data(:,1);          %Output gap 
r = Data(:,2);          %Fed funds rate
p = Data(:,3);          %Inflation gap
T = size(y,1);          %Number of observations
iota=ones(T,1);         %Vector of ones
 LHS=r;                  %The fed funds rate is the left-hand-side variable
RHS=[iota y p];
results=ols(LHS,RHS);
Warning: Matrix is singular, close to singular or badly scaled. Results may be inaccurate. RCOND = NaN. 
> In ols (line 53)
 
>> LHS=r;