g/1998/Math/MathML"><semantics><mi>ùêê</mi><annotation encoding="application/x-tex">\mathbf{Q}</annotation></semantics></math>
is the orthonormal matrix corresponding to <code>Z</code> and
<math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mi>ùêë</mi><annotation encoding="application/x-tex">\mathbf{R}</annotation></semantics></math>
is an upper triangular matrix. However, the signs of the columns of
<math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><sem