
function model = reg_least_sq_model(m,sigma1,sigma2)

% convert standard deviation specs to lambda parameters.
lambda1 = sqrt(2)/sigma1;
lambda2 = sqrt(2)/sigma2;

% generate random coefficients sampled from laplacian pdf
b = laplacian_deviates(m,1,lambda1);
A = laplacian_deviates(m,m,lambda2);
for i = 1:m
  A(i,i) = 0.0; % no x_i^2 terms, just cross-terms x_i x_j (i ~= j)
end

model = struct('A',A,'b',b,'m',m);

