ModSim ass4 taddeus: Updated Least Squares usage.

modsim/ass4_taddeus/ring/plot.py

 #!/usr/bin/env python
 from sys import argv, stdin
-from pylab import array, matrix, ones, dot, plot, legend, show, savefig
+from pylab import plot, xlabel, ylabel, legend, show, savefig
+from scipy import polyfit, polyval
 
 # Collect data
-data = []
+x = []
+y = []
 for line in stdin.readlines():
-    data.append(map(float, line.split(',', 1)))
+    s, t = map(float, line.split(',', 1))
+    x.append(s)
+    y.append(t)
 
 # Least squares data fit
-A = matrix(ones((len(data), 2)))
-data = array(data)
-A.T[1] = data.T[0]
-b = data.T[1].T
-start, slope = tuple(list(dot((A.T * A).I * A.T, b).tolist()[0]))
+c = tuple(polyfit(x, y, 1).tolist())
+fit = polyval(c, [0, x[-1]])
 
 # Plot and optionally save data
-data = data.T
-plot(data[0], data[1], 'x', label='original data')
-plot([0, data[0][-1]], [start, data[0][-1] * slope + start], '-',
-     label='linear fit y = %ex + %e' % (slope, start))
+plot(x, y, 'x', label='metingen')
+plot([0, x[-1]], fit, '-', label='Least Squares fit (y = %ex + %e)' % c)
 legend()
+xlabel('Pakketgrootte')
+ylabel('Tijd (s)')
 if len(argv) == 2:
     savefig(argv[1])
 show()

modsim/ass4_taddeus/ring/ring.c

@@ -3,9 +3,9 @@
 #include <math.h>
 #include <mpi.h>
 
-#define DEBUG
+//#define DEBUG
 
-#define LOOP 1        // Number of different message sizes
+#define LOOP 100        // Number of different message sizes
 #define STRIDE 10000    // Difference between the message sizes
 #define REPEAT 7        // Number of times to repeat aREPEAT measurement