roc_plot.py

#!/usr/bin/env python

from pylab import *
from matplotlib import rcParams
from pprint import pprint
import sys
from itertools import permutations

def main():
 filename = sys.argv[1]
 input = open(filename, 'r')

 result = []
 wt_score = 0.0
 for line in input:
 if line[0] == '#': continue
 data = line.split()
 #if len(data) == 2:
 if 'WT' in line:
 wt_score = eval(data[1])
 elif len(data) > 2:
 diff = eval(data[1]) - wt_score
 label = data[2]
 result.append((diff, label))

 result.sort(key = lambda tup : tup[0], reverse = True)
 pprint(result)

 T, F = 0, 0
 x, y = [0.0], [0.0]
 for (diff, label) in result:
 if label == 'T': T += 1
 else: F += 1
 x.append(F)
 y.append(T)

 x = [a / (F + 0.0) for a in x]
 y = [b / (T + 0.0) for b in y]

 old_x = 0.0
 area = 0.0
 for i in range(len(x)):
 width = x[i] - old_x
 area += width * y[i]
 old_x = x[i]
 print "Area under curve is: %.3f" % area

 # Plotting
 # set up the font
 rcParams['font.family'] = 'sans-serif'
 rcParams['font.sans-serif'] = 'Lucida Grande'
 rcParams['axes.labelsize'] = 14

 plot(x, y, marker = 'o', markersize = 4.0, linestyle = 'solid', c = '#000000', linewidth = 2.0)
 t = np.arange(0.0, 1.2, 0.2)

 plot(t, t, c = '#990000', linestyle = 'dashed', linewidth = 2.0)
 xlabel("False Positive Rate")
 ylabel("True Positive Rate")
 ylim([0, 1.01])
 xlim([-0.01, 1.01])
 show()

main()