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Revert using unweighted variance in weight calculation

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This reverts commit 165e6805ab.
This commit is contained in:
Miroslav Lichvar
2011-04-28 17:12:39 +02:00
parent 7f12919fea
commit 66c7ac4d24
3 changed files with 9 additions and 18 deletions
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14
sourcestats.c
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@@ -105,9 +105,6 @@ struct SST_Stats_Record {
/* This is the estimated residual variance of the data points */
double variance;
/* This is the estimated unweighted variance of the data points */
double uvariance;
/* This array contains the sample epochs, in terms of the local
clock. */
struct timeval sample_times[MAX_SAMPLES * REGRESS_RUNS_RATIO];
@@ -193,7 +190,7 @@ SST_CreateInstance(unsigned long refid, IPAddr *addr)
inst->estimated_offset_sd = 86400.0; /* Assume it's at least within a day! */
inst->offset_time.tv_sec = 0;
inst->offset_time.tv_usec = 0;
inst->variance = inst->uvariance = 16.0;
inst->variance = 16.0;
inst->nruns = 0;
return inst;
}
@@ -367,7 +364,7 @@ find_min_delay_sample(SST_Stats inst)
time. E.g. a value of 4 means that we think the standard deviation
is four times the fluctuation of the peer distance */
#define SD_TO_DIST_RATIO 1.4
#define SD_TO_DIST_RATIO 1.0
/* ================================================== */
/* This function runs the linear regression operation on the data. It
@@ -385,7 +382,7 @@ SST_DoNewRegression(SST_Stats inst)
int degrees_of_freedom;
int best_start, times_back_start;
double est_intercept, est_slope, est_var, est_uvar, est_intercept_sd, est_slope_sd;
double est_intercept, est_slope, est_var, est_intercept_sd, est_slope_sd;
int i, j, nruns;
double min_distance;
double sd_weight, sd;
@@ -408,7 +405,7 @@ SST_DoNewRegression(SST_Stats inst)
/* And now, work out the weight vector */
sd = sqrt(inst->uvariance);
sd = sqrt(inst->variance);
if (sd > min_distance || sd <= 0.0)
sd = min_distance;
@@ -421,7 +418,7 @@ SST_DoNewRegression(SST_Stats inst)
inst->regression_ok = RGR_FindBestRegression(times_back + inst->runs_samples,
offsets + inst->runs_samples, weights,
inst->n_samples, inst->runs_samples,
&est_intercept, &est_slope, &est_var, &est_uvar,
&est_intercept, &est_slope, &est_var,
&est_intercept_sd, &est_slope_sd,
&best_start, &nruns, &degrees_of_freedom);
@@ -436,7 +433,6 @@ SST_DoNewRegression(SST_Stats inst)
inst->offset_time = inst->sample_times[inst->last_sample];
inst->estimated_offset_sd = est_intercept_sd;
inst->variance = est_var;
inst->uvariance = est_uvar;
inst->nruns = nruns;
stress = fabs(old_freq - inst->estimated_frequency) / old_skew;