| |
| template <typename Scalar> |
| void ei_rwupdt(int n, Scalar *r__, int ldr, |
| const Scalar *w, Scalar *b, Scalar *alpha, Scalar *cos__, |
| Scalar *sin__) |
| { |
| /* System generated locals */ |
| int r_dim1, r_offset; |
| |
| /* Local variables */ |
| int i, j, jm1; |
| Scalar tan__, temp, rowj, cotan; |
| |
| /* Parameter adjustments */ |
| --sin__; |
| --cos__; |
| --b; |
| --w; |
| r_dim1 = ldr; |
| r_offset = 1 + r_dim1 * 1; |
| r__ -= r_offset; |
| |
| /* Function Body */ |
| |
| for (j = 1; j <= n; ++j) { |
| rowj = w[j]; |
| jm1 = j - 1; |
| |
| /* apply the previous transformations to */ |
| /* r(i,j), i=1,2,...,j-1, and to w(j). */ |
| |
| if (jm1 < 1) { |
| goto L20; |
| } |
| for (i = 1; i <= jm1; ++i) { |
| temp = cos__[i] * r__[i + j * r_dim1] + sin__[i] * rowj; |
| rowj = -sin__[i] * r__[i + j * r_dim1] + cos__[i] * rowj; |
| r__[i + j * r_dim1] = temp; |
| /* L10: */ |
| } |
| L20: |
| |
| /* determine a givens rotation which eliminates w(j). */ |
| |
| cos__[j] = 1.; |
| sin__[j] = 0.; |
| if (rowj == 0.) { |
| goto L50; |
| } |
| if (ei_abs(r__[j + j * r_dim1]) >= ei_abs(rowj)) |
| goto L30; |
| cotan = r__[j + j * r_dim1] / rowj; |
| /* Computing 2nd power */ |
| sin__[j] = Scalar(.5) / ei_sqrt(Scalar(0.25) + Scalar(0.25) * ei_abs2(cotan)); |
| cos__[j] = sin__[j] * cotan; |
| goto L40; |
| L30: |
| tan__ = rowj / r__[j + j * r_dim1]; |
| /* Computing 2nd power */ |
| cos__[j] = Scalar(.5) / ei_sqrt(Scalar(0.25) + Scalar(0.25) * ei_abs2(tan__)); |
| sin__[j] = cos__[j] * tan__; |
| L40: |
| |
| /* apply the current transformation to r(j,j), b(j), and alpha. */ |
| |
| r__[j + j * r_dim1] = cos__[j] * r__[j + j * r_dim1] + sin__[j] * |
| rowj; |
| temp = cos__[j] * b[j] + sin__[j] * *alpha; |
| *alpha = -sin__[j] * b[j] + cos__[j] * *alpha; |
| b[j] = temp; |
| L50: |
| /* L60: */ |
| ; |
| } |
| return; |
| |
| /* last card of subroutine rwupdt. */ |
| |
| } /* rwupdt_ */ |
| |
