From 7fb7f95979de6ab90557478e89fa74e9fc15fce3 Mon Sep 17 00:00:00 2001 From: Miroslav Lichvar Date: Wed, 21 Jun 2017 17:48:26 +0200 Subject: [PATCH] sourcestats: include precision in weight calculation In order to stabilize the weights of refclock samples which have only slightly different distances, don't allow the stddev value used in the weight calculation to be smaller than the precision and also assign weight of 1 to all samples which have distance < minimum + precision. --- sourcestats.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/sourcestats.c b/sourcestats.c index d8d4246..a18b8b2 100644 --- a/sourcestats.c +++ b/sourcestats.c @@ -51,9 +51,6 @@ #define MIN_SKEW 1.0e-12 #define MAX_SKEW 1.0e+02 -/* The minimum assumed std dev for weighting */ -#define MIN_WEIGHT_SD 1.0e-9 - /* The asymmetry of network jitter when all jitter is in one direction */ #define MAX_ASYMMETRY 0.5 @@ -489,6 +486,7 @@ SST_DoNewRegression(SST_Stats inst) double min_distance, mean_distance; double sd_weight, sd; double old_skew, old_freq, stress; + double precision; convert_to_intervals(inst, times_back + inst->runs_samples); @@ -510,11 +508,15 @@ SST_DoNewRegression(SST_Stats inst) /* And now, work out the weight vector */ - sd = mean_distance - min_distance; - sd = CLAMP(MIN_WEIGHT_SD, sd, min_distance); + precision = LCL_GetSysPrecisionAsQuantum(); + sd = (mean_distance - min_distance) / SD_TO_DIST_RATIO; + sd = CLAMP(precision, sd, min_distance); + min_distance += precision; for (i=0; in_samples; i++) { - sd_weight = 1.0 + SD_TO_DIST_RATIO * (peer_distances[i] - min_distance) / sd; + sd_weight = 1.0; + if (peer_distances[i] > min_distance) + sd_weight += (peer_distances[i] - min_distance) / sd; weights[i] = sd_weight * sd_weight; } }