src/nws_portability/Forecast/run_mean.c

   1 /* $Id$ */
   2
   3 #include <unistd.h>
   4 #include <stdlib.h>
   5 #include <stdio.h>
   6 #include <math.h>
   7 #include <string.h>
   8 #include <strings.h>
   9
  10 #include "fbuff.h"
  11 #include "run_mean.h"
  12
  13 struct run_mean_state
  14 {
  15         fbuff series;                   /* the series so far */
  16         fbuff time_stamps;              /* the time stamps */
  17         double total;
  18         double count;
  19 };
  20
  21 /*
  22  * init local state.  can save a copy of the pointer to the
  23  * series and time stamps, if desired
  24  */
  25 char *
  26 InitRunMean(fbuff series, fbuff time_stamps, char *params)
  27 {
  28         struct run_mean_state *state;
  29
  30         state = (struct run_mean_state *)
  31                 malloc(sizeof(struct run_mean_state));
  32
  33         if(state == NULL)
  34         {
  35                 return(NULL);
  36         }
  37
  38         /*
  39          * all functions take a forcb
  40          */
  41         state->series = series;
  42         state->time_stamps = time_stamps;
  43         state->total = 0.0;
  44         state->count = 0.0;
  45
  46         return((char *)state);
  47 }
  48
  49 void
  50 FreeRunMean(char *state)
  51 {
  52         free(state);
  53         return;
  54 }
  55
  56 void
  57 UpdateRunMean(char *state,
  58                 double ts,
  59                 double value)
  60 {
  61         struct run_mean_state *s;
  62
  63         s = (struct run_mean_state *)state;
  64
  65         s->total += value;
  66         s->count += 1.0;
  67         return;
  68 }
  69
  70 int
  71 ForcRunMean(char *state, double *v)
  72 {
  73         double val;
  74         struct run_mean_state *s = (struct run_mean_state *)state;
  75
  76         if(s->count != 0.0)
  77         {
  78                 val = s->total / s->count;
  79                 *v = val;
  80                 return(1);
  81         }
  82         else
  83         {
  84                 *v = 0.0;
  85                 return(0);
  86         }
  87 }
  88
  89