SMPI's network model calibration script: you give it information about your platform...

git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/simgrid/simgrid/trunk@8341 48e7efb5-ca39-0410-a469-dd3cf9ba447f

diff --git a/contrib/network_model/calibrate_piecewise.py b/contrib/network_model/calibrate_piecewise.py
new file mode 100755 (executable)
index 0000000..6d05b83
--- /dev/null
+++ b/contrib/network_model/calibrate_piecewise.py
@@ -0,0 +1,95 @@
+#!/usr/bin/env python
+
+import sys
+from math import sqrt
+
+
+if len(sys.argv) < 5:
+   print("Usage : %s datafile links latency bandwidth [size...]" % sys.argv[0])
+   print("where : links is the number of links between nodes")
+   print("        latency is the nominal latency given in the platform file")
+   print("        bandwidth is the nominal bandwidth given in the platform file")
+   print("        size are segments limites")
+   sys.exit(-1)
+
+##-----------------------------------------
+## avg : return average of a list of values
+## param l list of values
+##-----------------------------------------
+def avg (l):
+   sum = 0
+   for e in l:
+      sum += float(e);
+   return sum / len(l)
+
+##-------------------------------------------------
+## cov : covariance
+## param X first data vector (..x_i..)
+## param Y second data vector (..x_i..)
+## = 1/n \Sum_{i=1}^n (x_i - avg(x)) * (y_i - avg(y))
+##--------------------------------------------------
+def cov (X, Y):
+   assert len(X) == len(Y)
+   n = len(X)   #  n=len(X)=len(Y)
+   avg_X = avg(X)
+   avg_Y = avg(Y)
+   S_XY = 0.0
+   for i in xrange(n):
+      S_XY += (X[i] - avg_X) * (Y[i] - avg_Y)
+   return (S_XY / n)
+
+##----------------------------------
+## variance : variance
+## param X data vector ( ..x_i.. )
+## (S_X)^2 = (Sum ( x_i - avg(x) )^2 ) / n
+##----------------------------------
+def variance (X):
+   n = len(X)
+   avg_X = avg (X)
+   S_X2 = 0.0
+   for i in xrange(n):
+      S_X2 += (X[i] - avg_X) ** 2
+   return (S_X2 / n)
+
+def calibrate (links, latency, bandwidth, sizes, timings):
+   assert len(sizes) == len(timings)
+   if len(sizes) < 2:
+      return None
+   S_XY = cov(sizes, timings)
+   S_X2 = variance(sizes)
+   a = S_XY / S_X2
+   b = avg(timings) - a * avg(sizes)
+   return (b * 1e-6) / (latency * links), 1e6 / (a * bandwidth)
+
+##-----------------------------------------------------------------------------------------------
+## main
+##-----------------------------------------------------------------------------------------------
+links = int(sys.argv[2])
+latency = float(sys.argv[3])
+bandwidth = float(sys.argv[4])
+skampidat = open(sys.argv[1], "r")
+
+timings = []
+sizes = []
+for line in skampidat:
+   l = line.split();
+   if line[0] != '#' and len(l) >= 3:   # is it a comment ?
+      ## expected format
+      ## ---------------
+      #count= 8388608  8388608  144916.1       7.6       32  144916.1  143262.0
+      #("%s %d %d %f %f %d %f %f\n" % (countlbl, count, countn, time, stddev, iter, mini, maxi)
+      timings.append(float(l[3]) / links)
+      sizes.append(int(l[1]))
+
+limits = []
+if len(sys.argv) > 5:
+   for i in xrange(5, len(sys.argv)):
+      limits += [idx for idx in xrange(len(sizes)) if sizes[idx] == int(sys.argv[i])]
+limits.append(len(sizes) - 1)
+
+low = 0
+for lim in limits:
+   correc = calibrate(links, latency, bandwidth, sizes[low:lim + 1], timings[low:lim + 1])
+   if correc:
+      print("Segment [%d:%d] -- Latency factor=%g -- Bandwidth factor=%g" % (sizes[low], sizes[lim], correc[0], correc[1]))
+   low = lim + 1