lsqnonneg function without constraints

lsqnonneg function of MATLAB helps to find value of x that minimizes norm of|C*x - d| subject to x >= 0. However, I want to find value of x that minimizes norm of|C*x - d| without any constraints. Is there some function in MATLAB to do so?

Answer 1

[John D'Errico]

Um, zillions of them?

lsqcov, regress, fit, lsqlin, lsqr, and that ignores all the nonlinear iterative solvers.

Turns out the most trivial, is just

x = C\d;