1 files changed, 16 insertions, 33 deletions
diff --git a/ckcptime.awk b/ckcptime.awk
index 4bc9539..df5e188 100644
--- a/ckcptime.awk
+++ b/ckcptime.awk
@@ -1,14 +1,10 @@
 #!/usr/bin/env awk -f
 
 
-function log10(n) {
+function log10(n) { return log(n)/log(10.0) }
 
-    return log(n)/log(10.0)
 
-}
-
-
-function merge_meas(val_est, unc_est, val_meas, unc_meas) {
+function merge_meas(est_val, est_unc, meas_val, meas_unc) {
 
     # add (meas - est) delta to the measurement uncertainty
     # note: this works when tracking a constant value,
@@ -16,17 +12,18 @@ function merge_meas(val_est, unc_est, val_meas, unc_meas) {
     # unc_meas = sqrt(unc_meas^2.0 + (val_meas - val_est)^2.0)
 
     # Kalman filtering compares variances
-    unc_est = (0.5*unc_est)^2.0
-    unc_meas = (0.5*unc_meas)^2.0
+    # convert uncertainties to square units
+    est_unc = (0.5*est_unc)^2.0
+    meas_unc = (0.5*meas_unc)^2.0
 
-    G_K = (unc_est)/((unc_est) + (unc_meas))
-    val_est = val_est + G_K*(val_meas - val_est)
-    unc_est = (unc_est*unc_meas)/(unc_est + unc_meas)
+    K = (est_unc)/((est_unc) + (meas_unc))
+    est_val = est_val + K*(meas_val - est_val)
+    est_unc = (est_unc*meas_unc)/(est_unc + meas_unc)
 
-    # convert unc_est back to same units as val_est
-    unc_est = 2.0*sqrt(unc_est)
+    # convert est_unc back to original units
+    est_unc = 2.0*sqrt(est_unc)
 
-    return sprintf(OFMT OFS OFMT ORS, val_est, unc_est)
+    return sprintf(OFMT OFS OFMT ORS, est_val, est_unc)
 
 }
 
@@ -36,7 +33,8 @@ function sigfig(val, unc) {
     ordmag_val = log10(val)
     ordmag_unc = log10(unc)
 
-    sigfig_unc = sprintf("%.f", 6)
+    #sigfig_unc = sprintf("%.f", 6)
+    sigfig_unc = sprintf("%.f", sqrt((ordmag_val - ordmag_unc)^2.0) + 1.0)
     sigfig_val = sprintf("%.f", (ordmag_val - ordmag_unc + sigfig_unc))
 
     ofmt_val = "%." sigfig_val "g"
@@ -47,24 +45,6 @@ function sigfig(val, unc) {
 }
 
 
-function ck_boottime() {
-
-    "sysctl kern.boottime" | getline t_kboot
-    close("sysctl kern.boottime")
-    sub("^.*\{", "", t_kboot)
-    sub("\}.*$", "", t_kboot)
-    split(t_kboot, t_kboot_arr, ",")
-
-    for (i in t_kboot_arr) {
-        sub("^.*= ", "", t_kboot_arr[i])
-    }
-
-    t_kboot = sprintf(t_kboot_arr[1] "." t_kboot_arr[2])
-    return t_kboot
-
-}
-
-
 function ck_cptime() {
 
     t_sys_meas[1] = systime()
@@ -155,6 +135,9 @@ function ck_uptime(t0_est, t0_unc) {
 BEGIN {
 
     OFMT="%.21g"
+    pi = 4.0*atan2(1.0, 1.0)
+    c0 = 299792458  # m/sec
+
     #print("_systime_", systime())
     #print("_boottime_", ck_boottime())
     printf("%s" ORS, ck_cptime())