Run Differential

baseballruns

#!/usr/bin/python

from scipy import stats
from pylab import *

# Read in the data.
mlb = loadtxt('mlb.txt', dtype=[('team', 'S3'), ('w', 'i'), ('l', 'i'), ('pct', 'f'),  ('rdiff', 'i')])

# Plot the data with invisible points.
scatter(mlb['rdiff'], mlb['w'], s=0)
xlabel('Run differential')
ylabel('Wins')

# Put team names at the data points.
for (t, w, rd) in zip(mlb['team'], mlb['w'], mlb['rdiff']):
	text(rd, w, t, size=9,
		horizontalalignment='center', verticalalignment='center')

# Perform the linear regression
m, b, r, p, stderr = stats.linregress(mlb['rdiff'], mlb['w'])

# Get endpoints of regression line and plot it.
rdMin = min(mlb['rdiff'])
wMin = m*rdMin + b
rdMax = max(mlb['rdiff'])
wMax = m*rdMax + b
plot([rdMin, rdMax], [wMin, wMax])

show()