diff options
| author | Yuval Adam <yuv.adm@gmail.com> | 2014-08-08 14:42:07 +0300 |
|---|---|---|
| committer | Yuval Adam <yuv.adm@gmail.com> | 2014-08-08 14:42:07 +0300 |
| commit | a6163888f3c56123b1db313743c6147ba498732c (patch) | |
| tree | ff7d15d991d1d09ba6cbc0cec80924f57445bfdd /third_party/ptpd-1.1.0/tools/offset_stats.m | |
| parent | c3e4c9a25c2910d2d66d52215b3406b13d5b23d5 (diff) | |
Add third_party libs
Diffstat (limited to 'third_party/ptpd-1.1.0/tools/offset_stats.m')
| -rw-r--r-- | third_party/ptpd-1.1.0/tools/offset_stats.m | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/third_party/ptpd-1.1.0/tools/offset_stats.m b/third_party/ptpd-1.1.0/tools/offset_stats.m new file mode 100644 index 0000000..26af4c2 --- /dev/null +++ b/third_party/ptpd-1.1.0/tools/offset_stats.m @@ -0,0 +1,102 @@ +#!/usr/bin/octave -qf
+
+printf("start\n");
+
+load t;
+load tr;
+
+# time window to analyze
+t_beg = 1;
+t_fin = length(t);
+
+# parameters for synthetic reference time
+#start_time = round(t(t_beg));
+#sample_interval = 1;
+
+# parameters for histogram
+h_beg = -15e-6;
+h_fin = 15e-6;
+h_sz = 1e-6;
+
+# parameters for allan variance
+# tune for your computational power
+tau_beg = 1;
+tau_fin = length(t)/10;
+tau_maxsamps = 100;
+
+# ----------
+
+printf("data loaded\n");
+
+# create synthetic reference time
+#tr = t;
+#tr(t_beg) = start_time;
+#for k = (t_beg+1):t_fin
+#
+# tr(k) = tr(k-1) + sample_interval;
+#
+#endfor
+
+# time offset computation
+o = t - tr;
+
+o_min = min(o(t_beg:t_fin));
+o_max = max(o(t_beg:t_fin));
+o_mean = mean(o(t_beg:t_fin));
+
+# relative tick rate computation
+r = t;
+for k = (t_beg+1):t_fin
+
+ r(k) = o(k) - o(k-1);
+
+endfor
+
+r_min = min(r((t_beg+1):t_fin));
+r_max = max(r((t_beg+1):t_fin));
+r_mean = mean(r((t_beg+1):t_fin));
+
+figure;
+h_bins = h_beg:h_sz:h_fin;
+hist( o(t_beg:t_fin), h_bins, 1);
+
+printf("histogram plotted\n");
+
+figure;
+subplot(211);
+plot( t_beg:t_fin, o(t_beg:t_fin), "r;time offset;",
+ [t_beg t_fin], [o_min o_min], "g;;",
+ [t_beg t_fin], [o_max o_max], "g;;",
+ [t_beg t_fin], [o_mean o_mean], "b;;");
+subplot(212);
+plot( (t_beg+1):t_fin, r((t_beg+1):t_fin), "r;relative tick rate;",
+ [(t_beg+1) t_fin], [r_min r_min], "g;;",
+ [(t_beg+1) t_fin], [r_max r_max], "g;;",
+ [(t_beg+1) t_fin], [r_mean r_mean], "b;;")
+replot;
+
+printf("offset plotted\n");
+
+# the allan vaiance computation from the IEEE 1588 spec
+a = t;
+for tau = tau_beg:tau_fin
+
+ beg = t_beg;
+ if (t_fin-2*tau) > tau_maxsamps
+ fin = tau_maxsamps;
+ else
+ fin = (t_fin-2*tau);
+ end
+
+ a(tau) = sum((t(beg:fin) - 2*t((beg+tau):(fin+tau)) + t((beg+2*tau):(fin+2*tau))).^2);
+ a(tau) /= 2*(fin-beg)*(tau^2);
+
+endfor
+
+figure;
+loglog( tau_beg:tau_fin, a(tau_beg:tau_fin), ";allan variance;");
+replot;
+
+printf("variance plotted\n");
+input("done\n");
+
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