From 3fcd6b3c59a99f906eabcef6d445334f9f82b8ee Mon Sep 17 00:00:00 2001
From: Phil Hord <hordp@cisco.com>
Date: Fri, 13 Dec 2013 08:15:31 -0500
Subject: [PATCH] deriv.awk: Calculate derivative of every column

Instead of just two columns (x and y) in the trace file, treat
every column as a function and calculate the first derivative
of it without regard for its supposed "meaning".  In addition
to getting more data from this, it also allows us to calculate
the 2nd derivative easily by running the script again on the
resulting data.

Also convert time in column 1 from microseconds to seconds.
---
 tools/deriv.awk        | 41 +++++++++++++++++------------------------
 tools/velocity_plot.sh | 13 ++++++++++---
 2 files changed, 27 insertions(+), 27 deletions(-)

diff --git a/tools/deriv.awk b/tools/deriv.awk
index 5736b62..b7faf5a 100755
--- a/tools/deriv.awk
+++ b/tools/deriv.awk
@@ -3,33 +3,26 @@ BEGIN { firstline = 1 }
 
 # Calculates the first derivative of columns 2 and 3 wrt column 1
 $0 !~ /^#/ {
-  t = $1
-  x = $2
-  y = $3
+  $1 /= 1000000.0
   if (firstline == 1) {
-    old_tx = old_ty = t
-    old_x = x
-    old_y = y
-    dy_dt = dx_dt = 0
+    for ( i=1; i<=NF; i++) {
+      prev_t[i] = $1
+      prev_x[i] = $i
+      deriv[i] = 0
+    }
     firstline = 0
   } else {
-    dx = old_x - x
-    dy = old_y - y
-
-    if ( dx != 0) {
-      dt = old_tx - t
-      dx_dt = dx/dt
-      old_tx = t
-      old_x = x
-    }
-    if ( dy != 0) {
-      dt = old_ty - t
-      dy_dt = dy/dt
-      old_ty = t
-      old_y = y
-    }
-    if ( dx != 0 || dy != 0 ) {
-      print t, " ", x, " ", y, " ", dx_dt, " ", dy_dt
+    printf $1
+    for ( i=2; i<=NF; i++) {
+      if ( $i != prev_x[i] ) {
+        dx = $i - prev_x[i]
+        dt = $1 - prev_t[i]
+        deriv[i] = dx/dt
+        prev_t[i] = $1
+        prev_x[i] = $i
+      }
+      printf " %s %0f", $i, deriv[i]
     }
+    print ""
   }
 }
diff --git a/tools/velocity_plot.sh b/tools/velocity_plot.sh
index e2d9fed..f3c7504 100755
--- a/tools/velocity_plot.sh
+++ b/tools/velocity_plot.sh
@@ -24,7 +24,14 @@ gnuplot --persist -e "
   set y2label 'Velocity (mm/minute)'; set ytics nomirror ; set y2tics;
   set samples 10000 ;
 
-  plot '${VELOC}' u (\$1/1000000):(\$2/$MM_PER_STEP) with lines t \"X-position\" , '' u (\$1/1000000):(\$3/$MM_PER_STEP) with lines t \"Y-position\"
-     , '' u (\$1/1000000):(60000000.0*\$4/$MM_PER_STEP) with lines t \"X-velocity\" axes x1y2
-     , '' u (\$1/1000000):(60000000.0*\$5/$MM_PER_STEP) with lines t \"Y-velocity\" axes x1y2
+  plot '${VELOC}' u (\$1):(60.0*\$3/$MM_PER_STEP) with lines t \"X-velocity\" axes x1y2
+     , '' u (\$1):(60.0*\$5/$MM_PER_STEP) with lines t \"Y-velocity\" axes x1y2
+     , '' u (\$1):(60.0*\$7/$MM_PER_STEP) with lines t \"Z-velocity\" axes x1y2
+     , '' u (\$1):(60.0*\$9/$MM_PER_STEP) with lines t \"E-velocity\" axes x1y2
+     , '' u (\$1):(\$2/$MM_PER_STEP) with lines t \"X-position\"
+     , '' u (\$1):(\$4/$MM_PER_STEP) with lines t \"Y-position\"
+     , '' u (\$1):(\$6/$MM_PER_STEP) with lines t \"Z-position\"
+     , '' u (\$1):(\$8/$MM_PER_STEP) with lines t \"E-position\"
+     , '' u (\$1):(\$10/$MM_PER_STEP) with steps t \"X-Step\"
+     , '' u (\$1):(\$10/$MM_PER_STEP) with steps t \"Y-Step\"
 "