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diff --git a/gsl-1.9/interpolation/akima.c b/gsl-1.9/interpolation/akima.c
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+/* interpolation/akima.c
+ *
+ * Copyright (C) 1996, 1997, 1998, 1999, 2000 Gerard Jungman
+ *
+ * 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.
+ */
+
+/* Author: G. Jungman
+ */
+#include <config.h>
+#include <stdlib.h>
+#include <math.h>
+#include <gsl/gsl_errno.h>
+#include "integ_eval.h"
+#include <gsl/gsl_interp.h>
+
+typedef struct
+{
+ double * b;
+ double * c;
+ double * d;
+ double * _m;
+} akima_state_t;
+
+
+/* common creation */
+static void *
+akima_alloc (size_t size)
+{
+ akima_state_t *state = (akima_state_t *) malloc (sizeof (akima_state_t));
+
+ if (state == NULL)
+ {
+ GSL_ERROR_NULL("failed to allocate space for state", GSL_ENOMEM);
+ }
+
+ state->b = (double *) malloc (size * sizeof (double));
+
+ if (state->b == NULL)
+ {
+ free (state);
+ GSL_ERROR_NULL("failed to allocate space for b", GSL_ENOMEM);
+ }
+
+ state->c = (double *) malloc (size * sizeof (double));
+
+ if (state->c == NULL)
+ {
+ free (state->b);
+ free (state);
+ GSL_ERROR_NULL("failed to allocate space for c", GSL_ENOMEM);
+ }
+
+ state->d = (double *) malloc (size * sizeof (double));
+
+ if (state->d == NULL)
+ {
+ free (state->c);
+ free (state->b);
+ free (state);
+ GSL_ERROR_NULL("failed to allocate space for d", GSL_ENOMEM);
+ }
+
+ state->_m = (double *) malloc ((size + 4) * sizeof (double));
+
+ if (state->_m == NULL)
+ {
+ free (state->d);
+ free (state->c);
+ free (state->b);
+ free (state);
+ GSL_ERROR_NULL("failed to allocate space for _m", GSL_ENOMEM);
+ }
+
+ return state;
+}
+
+
+/* common calculation */
+static void
+akima_calc (const double x_array[], double b[], double c[], double d[], size_t size, double m[])
+{
+ size_t i;
+
+ for (i = 0; i < (size - 1); i++)
+ {
+ const double NE = fabs (m[i + 1] - m[i]) + fabs (m[i - 1] - m[i - 2]);
+ if (NE == 0.0)
+ {
+ b[i] = m[i];
+ c[i] = 0.0;
+ d[i] = 0.0;
+ }
+ else
+ {
+ const double h_i = x_array[i + 1] - x_array[i];
+ const double NE_next = fabs (m[i + 2] - m[i + 1]) + fabs (m[i] - m[i - 1]);
+ const double alpha_i = fabs (m[i - 1] - m[i - 2]) / NE;
+ double alpha_ip1;
+ double tL_ip1;
+ if (NE_next == 0.0)
+ {
+ tL_ip1 = m[i];
+ }
+ else
+ {
+ alpha_ip1 = fabs (m[i] - m[i - 1]) / NE_next;
+ tL_ip1 = (1.0 - alpha_ip1) * m[i] + alpha_ip1 * m[i + 1];
+ }
+ b[i] = (1.0 - alpha_i) * m[i - 1] + alpha_i * m[i];
+ c[i] = (3.0 * m[i] - 2.0 * b[i] - tL_ip1) / h_i;
+ d[i] = (b[i] + tL_ip1 - 2.0 * m[i]) / (h_i * h_i);
+ }
+ }
+}
+
+
+static int
+akima_init (void * vstate, const double x_array[], const double y_array[],
+ size_t size)
+{
+ akima_state_t *state = (akima_state_t *) vstate;
+
+ double * m = state->_m + 2; /* offset so we can address the -1,-2
+ components */
+
+ size_t i;
+ for (i = 0; i <= size - 2; i++)
+ {
+ m[i] = (y_array[i + 1] - y_array[i]) / (x_array[i + 1] - x_array[i]);
+ }
+
+ /* non-periodic boundary conditions */
+ m[-2] = 3.0 * m[0] - 2.0 * m[1];
+ m[-1] = 2.0 * m[0] - m[1];
+ m[size - 1] = 2.0 * m[size - 2] - m[size - 3];
+ m[size] = 3.0 * m[size - 2] - 2.0 * m[size - 3];
+
+ akima_calc (x_array, state->b, state->c, state->d, size, m);
+
+ return GSL_SUCCESS;
+}
+
+
+static int
+akima_init_periodic (void * vstate,
+ const double x_array[],
+ const double y_array[],
+ size_t size)
+{
+ akima_state_t *state = (akima_state_t *) vstate;
+
+ double * m = state->_m + 2; /* offset so we can address the -1,-2
+ components */
+
+ size_t i;
+ for (i = 0; i <= size - 2; i++)
+ {
+ m[i] = (y_array[i + 1] - y_array[i]) / (x_array[i + 1] - x_array[i]);
+ }
+
+ /* periodic boundary conditions */
+ m[-2] = m[size - 1 - 2];
+ m[-1] = m[size - 1 - 1];
+ m[size - 1] = m[0];
+ m[size] = m[1];
+
+ akima_calc (x_array, state->b, state->c, state->d, size, m);
+
+ return GSL_SUCCESS;
+}
+
+static void
+akima_free (void * vstate)
+{
+ akima_state_t *state = (akima_state_t *) vstate;
+
+ free (state->b);
+ free (state->c);
+ free (state->d);
+ free (state->_m);
+ free (state);
+}
+
+
+static
+int
+akima_eval (const void * vstate,
+ const double x_array[], const double y_array[], size_t size,
+ double x,
+ gsl_interp_accel * a,
+ double *y)
+{
+ const akima_state_t *state = (const akima_state_t *) vstate;
+
+ size_t index;
+
+ if (a != 0)
+ {
+ index = gsl_interp_accel_find (a, x_array, size, x);
+ }
+ else
+ {
+ index = gsl_interp_bsearch (x_array, x, 0, size - 1);
+ }
+
+ /* evaluate */
+ {
+ const double x_lo = x_array[index];
+ const double delx = x - x_lo;
+ const double b = state->b[index];
+ const double c = state->c[index];
+ const double d = state->d[index];
+ *y = y_array[index] + delx * (b + delx * (c + d * delx));
+ return GSL_SUCCESS;
+ }
+}
+
+
+static int
+akima_eval_deriv (const void * vstate,
+ const double x_array[], const double y_array[], size_t size,
+ double x,
+ gsl_interp_accel * a,
+ double *dydx)
+{
+ const akima_state_t *state = (const akima_state_t *) vstate;
+
+ size_t index;
+
+ DISCARD_POINTER(y_array); /* prevent warning about unused parameter */
+
+ if (a != 0)
+ {
+ index = gsl_interp_accel_find (a, x_array, size, x);
+ }
+ else
+ {
+ index = gsl_interp_bsearch (x_array, x, 0, size - 1);
+ }
+
+ /* evaluate */
+ {
+ double x_lo = x_array[index];
+ double delx = x - x_lo;
+ double b = state->b[index];
+ double c = state->c[index];
+ double d = state->d[index];
+ *dydx = b + delx * (2.0 * c + 3.0 * d * delx);
+ return GSL_SUCCESS;
+ }
+}
+
+
+static
+int
+akima_eval_deriv2 (const void * vstate,
+ const double x_array[], const double y_array[], size_t size,
+ double x,
+ gsl_interp_accel * a,
+ double *y_pp)
+{
+ const akima_state_t *state = (const akima_state_t *) vstate;
+
+ size_t index;
+
+ DISCARD_POINTER(y_array); /* prevent warning about unused parameter */
+
+ if (a != 0)
+ {
+ index = gsl_interp_accel_find (a, x_array, size, x);
+ }
+ else
+ {
+ index = gsl_interp_bsearch (x_array, x, 0, size - 1);
+ }
+
+ /* evaluate */
+ {
+ const double x_lo = x_array[index];
+ const double delx = x - x_lo;
+ const double c = state->c[index];
+ const double d = state->d[index];
+ *y_pp = 2.0 * c + 6.0 * d * delx;
+ return GSL_SUCCESS;
+ }
+}
+
+
+static
+int
+akima_eval_integ (const void * vstate,
+ const double x_array[], const double y_array[], size_t size,
+ gsl_interp_accel * acc,
+ double a, double b,
+ double * result)
+{
+ const akima_state_t *state = (const akima_state_t *) vstate;
+
+ size_t i, index_a, index_b;
+
+ if (acc != 0)
+ {
+ index_a = gsl_interp_accel_find (acc, x_array, size, a);
+ index_b = gsl_interp_accel_find (acc, x_array, size, b);
+ }
+ else
+ {
+ index_a = gsl_interp_bsearch (x_array, a, 0, size - 1);
+ index_b = gsl_interp_bsearch (x_array, b, 0, size - 1);
+ }
+
+ *result = 0.0;
+
+ /* interior intervals */
+
+ for(i=index_a; i<=index_b; i++) {
+ const double x_hi = x_array[i + 1];
+ const double x_lo = x_array[i];
+ const double y_lo = y_array[i];
+ const double dx = x_hi - x_lo;
+ if(dx != 0.0) {
+
+ if (i == index_a || i == index_b)
+ {
+ double x1 = (i == index_a) ? a : x_lo;
+ double x2 = (i == index_b) ? b : x_hi;
+ *result += integ_eval (y_lo, state->b[i], state->c[i], state->d[i],
+ x_lo, x1, x2);
+ }
+ else
+ {
+ *result += dx * (y_lo
+ + dx*(0.5*state->b[i]
+ + dx*(state->c[i]/3.0
+ + 0.25*state->d[i]*dx)));
+ }
+ }
+ else {
+ *result = 0.0;
+ return GSL_FAILURE;
+ }
+ }
+
+ return GSL_SUCCESS;
+}
+
+
+static const gsl_interp_type akima_type =
+{
+ "akima",
+ 5,
+ &akima_alloc,
+ &akima_init,
+ &akima_eval,
+ &akima_eval_deriv,
+ &akima_eval_deriv2,
+ &akima_eval_integ,
+ &akima_free
+};
+
+const gsl_interp_type * gsl_interp_akima = &akima_type;
+
+static const gsl_interp_type akima_periodic_type =
+{
+ "akima-periodic",
+ 5,
+ &akima_alloc,
+ &akima_init_periodic,
+ &akima_eval,
+ &akima_eval_deriv,
+ &akima_eval_deriv2,
+ &akima_eval_integ,
+ &akima_free
+};
+
+const gsl_interp_type * gsl_interp_akima_periodic = &akima_periodic_type;
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