Solves A X = B for a vector X,' where A is specified by the mxn array U, n'
vector W, and nxn matrix V as returned by svdcmp. m' and n' are the
dimensions of A,' and will be equal for square matrices. B' is the 1xm input
vector for the right-hand side. X' is the 1xn output solution vector. All<br> arrays are of double-floats. No input quantities are destroyed, so the routine<br> may be called sequentially with different B's. See the discussion in Numerical<br> Recipes in C, section 2.6.<br> <br> This routine assumes that near zero singular values have already been zeroed.<br> It returns no values, storing the result in X.' It does use some auxiliary
storage, which can be passed in as tmp,' a double-float array of length n,' if
you want to avoid consing.