/** G. Rilling, last modification: 3.2007* gabriel.rilling@ens-lyon.fr** code based on a student project by T. Boustane and G. Quellec, 11.03.2004* supervised by P. Chainais (ISIMA - LIMOS - Universite Blaise Pascal - Clermont II* email : pchainai@isima.fr).*//********************************************************//* ALLOCATE MEMORY FOR THE ENVELOPES AND TEMPORARY DATA *//********************************************************/envelope_t init_local_mean(int n) {  envelope_t env;  env.e_min = (double*)malloc(n*sizeof(double));  env.e_max = (double*)malloc(n*sizeof(double));  env.tmp1 = (double*)malloc(n*sizeof(double));  env.tmp2 = (double*)malloc(n*sizeof(double));  return env;}/*************************//* FREE ALLOCATED MEMORY *//*************************/void free_local_mean(envelope_t env) {  free(env.e_min);  free(env.e_max);  free(env.tmp1);  free(env.tmp2);}/*********************************************************//* COMPUTES THE MEAN OF THE ENVELOPES OF THE CURRENT IMF *//*********************************************************/int mean(double *x,double *z,double *m,int n,extrema_t *ex,envelope_t *env) {  int i;  /* detect maxima and minima */  extr(x,z,n,ex);  /* if not enough extrema -> stop */  if (ex->n_min+ex->n_max <7)    return 1;  /* add extra points at the edges */  boundary_conditions(x,z,n,ex);  /* interpolation - upper envelope */  interpolation(env->e_max,ex->x_max,ex->y_max,ex->n_max,x,n,env->tmp1,env->tmp2);  /* interpolation - lower envelope */  interpolation(env->e_min,ex->x_min,ex->y_min,ex->n_min,x,n,env->tmp1,env->tmp2);  if ((ex->n_min > LIM_GMP)||(ex->n_min > LIM_GMP)) {    mexWarnMsgTxt("Too many extrema, interpolation may be unreliable\n");  }  /* compute the mean */  for (i=0;i<n;i++) m[i]=(env->e_max[i]+env->e_min[i])/2;  return 0;}/***************************************************************************//* COMPUTES THE MEAN OF THE ENVELOPES AND THE AMPLITUDE OF THE CURRENT IMF *//***************************************************************************/int mean_and_amplitude(double *x,double *z,double *m,double *a,int n,extrema_t *ex,envelope_t *env) {  int i;  /* detect maxima and minima */  extr(x,z,n,ex);  /* if not enough extrema -> stop */  if (ex->n_min+ex->n_max <7)    return 1;  /* add extra points at the edges */  boundary_conditions(x,z,n,ex);  /* interpolation - upper envelope */  interpolation(env->e_max,ex->x_max,ex->y_max,ex->n_max,x,n,env->tmp1,env->tmp2);  /* interpolation - lower envelope */  interpolation(env->e_min,ex->x_min,ex->y_min,ex->n_min,x,n,env->tmp1,env->tmp2);  /* compute the mean */  for (i=0;i<n;i++) m[i]=(env->e_max[i]+env->e_min[i])/2;  /* compute the amplitude */  for (i=0;i<n;i++) a[i]=(env->e_max[i]-env->e_min[i])/2;  return 0;}