function mle(Y, A, C) {
let AT = math.transpose(A);
let X = math.multiply(math.inv(
math.multiply(math.multiply(AT, math.inv(C)), A)), math.multiply(math.multiply(AT, math.inv(C)), Y));
let covX = math.inv(math.multiply(math.multiply(AT, math.inv(C)), A));
return {X:X, covX:covX}
}