diff -r 000000000000 -r 6474c204b198 tools/footprint/linear-regression.awk
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tools/footprint/linear-regression.awk	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,58 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+function regress(DATAPOINTS,SX,SY,SXY,SX2)
+{
+   b1 = (DATAPOINTS * SXY - SX * SY) / (DATAPOINTS * SX2 - SX * SX);
+   b0 = (SY - b1 * SX ) / DATAPOINTS;
+   return b1 " * x + " b0; 
+}
+
+BEGIN {
+        if (!Skip) Skip = 0;
+        if (Interval) 
+        {
+           Count = 0;
+           IntervalCount = 0;
+        }
+      }
+
+NR>Skip {
+        sx += $1;
+        sy += $2;
+        sxy += $1 * $2;
+        sx2 += $1 * $1;
+        #print NR " " sx " " sy " " sxy " " sx2
+
+        if (Interval)
+        {
+           if(Count == Interval-1)
+           {
+              IntervalCount += 1;
+
+              print NR-Count, "-", NR, ":  ", regress(Count,isx,isy,isxy,isx2);
+
+              Count = 0;
+              isx = 0;
+              isy = 0;
+              isxy = 0;
+              isx2 = 0;
+           }
+           else
+           {
+              Count += 1;
+              isx += $1;
+              isy += $2;
+              isxy += $1 * $2;
+              isx2 += $1 * $1;
+           }
+        }
+     }
+
+END {
+       if(Interval) {
+          print NR-Count, "-", NR, ":  ", regress(Count,isx,isy,isxy,isx2);
+       }
+       print regress(NR-Skip, sx, sy, sxy, sx2); 
+    }