scripts: plotcsv.py: Also plot linear and cubic interpolation of data

1 files changed, 9 insertions, 2 deletions

diff --git a/scripts/plotcsv.py b/scripts/plotcsv.py
index 32e96c5..931e4e8 100755
--- a/scripts/plotcsv.py
+++ b/scripts/plotcsv.py
@@ -3,6 +3,7 @@
 import csv
 import getopt
 import os, sys
+import scipy.interpolate
 import numpy as np
 import matplotlib.pyplot as plt
 
@@ -16,12 +17,18 @@ def read_and_plot_csv(csv_file, x_max=X_MAX, y_max=Y_MAX):
     reader = csv.reader(open(csv_file, 'r'), delimiter=',')
     x_name,y_name = reader.next() # header line
 
-    X = np.array([ [ float(_x), float(_y) ] for _x,_y in reader ])
+    X = np.array([[float(_x), float(_y)] for _x,_y in reader ])
     x = X[:,0]
     y = X[:,1]
 
+    # interpolate data points
+    xnew = np.linspace(min(x), max(x), len(x)*5)
+    f = scipy.interpolate.interp1d(x, y)
+    f2 = scipy.interpolate.interp1d(x, y, kind='cubic')
+
     fig = plt.figure()
-    plt.plot(x, y)
+    plt.plot(x, y, 'o', xnew, f(xnew), '-', xnew, f2(xnew), '--')
+    plt.legend(['data', 'linear interp.', 'cubic interp.'], loc='best')
     plt.axis([0, x_max, 0, y_max], 'equal')
     plt.xlabel(x_name)
     plt.ylabel(y_name)