src/mdlib/nlistheuristics.c

   1 /* -*- mode: c; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; c-file-style: "stroustrup"; -*-
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  36 #ifdef HAVE_CONFIG_H
  37 #include <config.h>
  38 #endif
  39
  40 #include "typedefs.h"
  41 #include "types/nlistheuristics.h"
  42 #include "gmx_fatal.h"
  43 #include "vec.h"
  44
  45 void reset_nlistheuristics(gmx_nlheur_t *nlh,gmx_large_int_t step)
  46 {
  47     nlh->lt_runav  = 0;
  48     nlh->lt_runav2 = 0;
  49     nlh->step_nscheck = step;
  50 }
  51
  52 void init_nlistheuristics(gmx_nlheur_t *nlh,
  53                           gmx_bool bGStatEveryStep,gmx_large_int_t step)
  54 {
  55     nlh->bGStatEveryStep = bGStatEveryStep;
  56     nlh->nns       = 0;
  57     nlh->nabnsb    = 0;
  58     nlh->s1        = 0;
  59     nlh->s2        = 0;
  60     nlh->ab        = 0;
  61
  62     reset_nlistheuristics(nlh,step);
  63 }
  64
  65 void update_nliststatistics(gmx_nlheur_t *nlh,gmx_large_int_t step)
  66 {
  67     gmx_large_int_t nl_lt;
  68     char sbuf[STEPSTRSIZE],sbuf2[STEPSTRSIZE];
  69
  70     /* Determine the neighbor list life time */
  71     nl_lt = step - nlh->step_ns;
  72     if (debug)
  73     {
  74         fprintf(debug,"%d atoms beyond ns buffer, updating neighbor list after %s steps\n",nlh->nabnsb,gmx_step_str(nl_lt,sbuf));
  75     }
  76     nlh->nns++;
  77     nlh->s1 += nl_lt;
  78     nlh->s2 += nl_lt*nl_lt;
  79     nlh->ab += nlh->nabnsb;
  80     if (nlh->lt_runav == 0)
  81     {
  82         nlh->lt_runav  = nl_lt;
  83         /* Initialize the fluctuation average
  84          * such that at startup we check after 0 steps.
  85          */
  86         nlh->lt_runav2 = sqr(nl_lt/2.0);
  87     }
  88     /* Running average with 0.9 gives an exp. history of 9.5 */
  89     nlh->lt_runav2 = 0.9*nlh->lt_runav2 + 0.1*sqr(nlh->lt_runav - nl_lt);
  90     nlh->lt_runav  = 0.9*nlh->lt_runav  + 0.1*nl_lt;
  91     if (nlh->bGStatEveryStep)
  92     {
  93         /* Always check the nlist validity */
  94         nlh->step_nscheck = step;
  95     }
  96     else
  97     {
  98         /* We check after:  <life time> - 2*sigma
  99          * The factor 2 is quite conservative,
 100          * but we assume that with nstlist=-1 the user
 101          * prefers exact integration over performance.
 102          */
 103         nlh->step_nscheck = step
 104                   + (int)(nlh->lt_runav - 2.0*sqrt(nlh->lt_runav2)) - 1;
 105     }
 106     if (debug)
 107     {
 108         fprintf(debug,"nlist life time %s run av. %4.1f sig %3.1f check %s check with -gcom %d\n",
 109                 gmx_step_str(nl_lt,sbuf),nlh->lt_runav,sqrt(nlh->lt_runav2),
 110                 gmx_step_str(nlh->step_nscheck-step+1,sbuf2),
 111                 (int)(nlh->lt_runav - 2.0*sqrt(nlh->lt_runav2)));
 112     }
 113 }
 114
 115 void set_nlistheuristics(gmx_nlheur_t *nlh,gmx_bool bReset,gmx_large_int_t step)
 116 {
 117     int d;
 118
 119     if (bReset)
 120     {
 121         reset_nlistheuristics(nlh,step);
 122     }
 123     else
 124     {
 125         update_nliststatistics(nlh,step);
 126     }
 127
 128     nlh->step_ns = step;
 129     /* Initialize the cumulative coordinate scaling matrix */
 130     clear_mat(nlh->scale_tot);
 131     for(d=0; d<DIM; d++)
 132     {
 133         nlh->scale_tot[d][d] = 1.0;
 134     }
 135 }