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diff --git a/gsl-1.9/linalg/hermtd.c b/gsl-1.9/linalg/hermtd.c
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+++ b/gsl-1.9/linalg/hermtd.c
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+/* linalg/hermtd.c
+ * 
+ * Copyright (C) 2001 Brian Gough
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+/* Factorise a hermitian matrix A into
+ *
+ * A = U T U'
+ *
+ * where U is unitary and T is real symmetric tridiagonal.  Only the
+ * diagonal and lower triangular part of A is referenced and modified.
+ *
+ * On exit, T is stored in the diagonal and first subdiagonal of
+ * A. Since T is symmetric the upper diagonal is not stored.
+ *
+ * U is stored as a packed set of Householder transformations in the
+ * lower triangular part of the input matrix below the first subdiagonal.
+ *
+ * The full matrix for Q can be obtained as the product
+ *
+ *       Q = Q_N ... Q_2 Q_1
+ *
+ * where 
+ *
+ *       Q_i = (I - tau_i * v_i * v_i')
+ *
+ * and where v_i is a Householder vector
+ *
+ *       v_i = [0, ..., 0, 1, A(i+2,i), A(i+3,i), ... , A(N,i)]
+ *
+ * This storage scheme is the same as in LAPACK.  See LAPACK's
+ * chetd2.f for details.
+ *
+ * See Golub & Van Loan, "Matrix Computations" (3rd ed), Section 8.3 */
+
+#include <config.h>
+#include <stdlib.h>
+#include <gsl/gsl_math.h>
+#include <gsl/gsl_vector.h>
+#include <gsl/gsl_matrix.h>
+#include <gsl/gsl_blas.h>
+#include <gsl/gsl_complex_math.h>
+
+#include <gsl/gsl_linalg.h>
+
+int 
+gsl_linalg_hermtd_decomp (gsl_matrix_complex * A, gsl_vector_complex * tau)  
+{
+  if (A->size1 != A->size2)
+    {
+      GSL_ERROR ("hermitian tridiagonal decomposition requires square matrix",
+                 GSL_ENOTSQR);
+    }
+  else if (tau->size + 1 != A->size1)
+    {
+      GSL_ERROR ("size of tau must be (matrix size - 1)", GSL_EBADLEN);
+    }
+  else
+    {
+      const size_t N = A->size1;
+      size_t i;
+  
+      const gsl_complex zero = gsl_complex_rect (0.0, 0.0);
+      const gsl_complex one = gsl_complex_rect (1.0, 0.0);
+      const gsl_complex neg_one = gsl_complex_rect (-1.0, 0.0);
+
+      for (i = 0 ; i < N - 1; i++)
+        {
+          gsl_vector_complex_view c = gsl_matrix_complex_column (A, i);
+          gsl_vector_complex_view v = gsl_vector_complex_subvector (&c.vector, i + 1, N - (i + 1));
+          gsl_complex tau_i = gsl_linalg_complex_householder_transform (&v.vector);
+          
+          /* Apply the transformation H^T A H to the remaining columns */
+
+          if ((i + 1) < (N - 1) 
+              && !(GSL_REAL(tau_i) == 0.0 && GSL_IMAG(tau_i) == 0.0)) 
+            {
+              gsl_matrix_complex_view m = 
+                gsl_matrix_complex_submatrix (A, i + 1, i + 1, 
+                                              N - (i+1), N - (i+1));
+              gsl_complex ei = gsl_vector_complex_get(&v.vector, 0);
+              gsl_vector_complex_view x = gsl_vector_complex_subvector (tau, i, N-(i+1));
+              gsl_vector_complex_set (&v.vector, 0, one);
+              
+              /* x = tau * A * v */
+              gsl_blas_zhemv (CblasLower, tau_i, &m.matrix, &v.vector, zero, &x.vector);
+
+              /* w = x - (1/2) tau * (x' * v) * v  */
+              {
+                gsl_complex xv, txv, alpha;
+                gsl_blas_zdotc(&x.vector, &v.vector, &xv);
+                txv = gsl_complex_mul(tau_i, xv);
+                alpha = gsl_complex_mul_real(txv, -0.5);
+                gsl_blas_zaxpy(alpha, &v.vector, &x.vector);
+              }
+              
+              /* apply the transformation A = A - v w' - w v' */
+              gsl_blas_zher2(CblasLower, neg_one, &v.vector, &x.vector, &m.matrix);
+
+              gsl_vector_complex_set (&v.vector, 0, ei);
+            }
+          
+          gsl_vector_complex_set (tau, i, tau_i);
+        }
+      
+      return GSL_SUCCESS;
+    }
+}  
+
+
+/*  Form the orthogonal matrix Q from the packed QR matrix */
+
+int
+gsl_linalg_hermtd_unpack (const gsl_matrix_complex * A, 
+                          const gsl_vector_complex * tau,
+                          gsl_matrix_complex * Q, 
+                          gsl_vector * diag, 
+                          gsl_vector * sdiag)
+{
+  if (A->size1 !=  A->size2)
+    {
+      GSL_ERROR ("matrix A must be sqaure", GSL_ENOTSQR);
+    }
+  else if (tau->size + 1 != A->size1)
+    {
+      GSL_ERROR ("size of tau must be (matrix size - 1)", GSL_EBADLEN);
+    }
+  else if (Q->size1 != A->size1 || Q->size2 != A->size1)
+    {
+      GSL_ERROR ("size of Q must match size of A", GSL_EBADLEN);
+    }
+  else if (diag->size != A->size1)
+    {
+      GSL_ERROR ("size of diagonal must match size of A", GSL_EBADLEN);
+    }
+  else if (sdiag->size + 1 != A->size1)
+    {
+      GSL_ERROR ("size of subdiagonal must be (matrix size - 1)", GSL_EBADLEN);
+    }
+  else
+    {
+      const size_t N = A->size1;
+
+      size_t i;
+
+      /* Initialize Q to the identity */
+
+      gsl_matrix_complex_set_identity (Q);
+
+      for (i = N - 1; i > 0 && i--;)
+        {
+          gsl_complex ti = gsl_vector_complex_get (tau, i);
+
+          gsl_vector_complex_const_view c = gsl_matrix_complex_const_column (A, i);
+
+          gsl_vector_complex_const_view h = 
+            gsl_vector_complex_const_subvector (&c.vector, i + 1, N - (i+1));
+
+          gsl_matrix_complex_view m = 
+            gsl_matrix_complex_submatrix (Q, i + 1, i + 1, N-(i+1), N-(i+1));
+
+          gsl_linalg_complex_householder_hm (ti, &h.vector, &m.matrix);
+        }
+
+      /* Copy diagonal into diag */
+
+      for (i = 0; i < N; i++)
+        {
+          gsl_complex Aii = gsl_matrix_complex_get (A, i, i);
+          gsl_vector_set (diag, i, GSL_REAL(Aii));
+        }
+
+      /* Copy subdiagonal into sdiag */
+
+      for (i = 0; i < N - 1; i++)
+        {
+          gsl_complex Aji = gsl_matrix_complex_get (A, i+1, i);
+          gsl_vector_set (sdiag, i, GSL_REAL(Aji));
+        }
+
+      return GSL_SUCCESS;
+    }
+}
+
+int
+gsl_linalg_hermtd_unpack_T (const gsl_matrix_complex * A, 
+                            gsl_vector * diag, 
+                            gsl_vector * sdiag)
+{
+  if (A->size1 !=  A->size2)
+    {
+      GSL_ERROR ("matrix A must be sqaure", GSL_ENOTSQR);
+    }
+  else if (diag->size != A->size1)
+    {
+      GSL_ERROR ("size of diagonal must match size of A", GSL_EBADLEN);
+    }
+  else if (sdiag->size + 1 != A->size1)
+    {
+      GSL_ERROR ("size of subdiagonal must be (matrix size - 1)", GSL_EBADLEN);
+    }
+  else
+    {
+      const size_t N = A->size1;
+
+      size_t i;
+
+      /* Copy diagonal into diag */
+
+      for (i = 0; i < N; i++)
+        {
+          gsl_complex Aii = gsl_matrix_complex_get (A, i, i);
+          gsl_vector_set (diag, i, GSL_REAL(Aii));
+        }
+
+      /* Copy subdiagonal into sd */
+
+      for (i = 0; i < N - 1; i++)
+        {
+          gsl_complex Aji = gsl_matrix_complex_get (A, i+1, i);
+          gsl_vector_set (sdiag, i, GSL_REAL(Aji));
+        }
+
+      return GSL_SUCCESS;
+    }
+}