ch3.py

from matplotlib import pyplot as plt
from collections import Counter

####
# dot-and-line Data
years = [1950, 1960, 1970, 1980, 1990, 2000, 2010]
gdp = [300.2, 543.3, 1075.9, 2862.5, 5979.6, 10289.7, 14958.3]

# Build up a dot-and-line plot
plt.plot(years, gdp, color='green', marker='o', linestyle='solid')
plt.title("Nominal GDP")
plt.ylabel("Billions of $")
plt.show()

###
# Bar Charts Movies data
movies = ["Annie Hall", "Ben Hur", "Casablanca", "Gandhi", "West Side Story"]
num_oscars = [5, 11, 3, 8, 10]

# Prep data so each bar is centered.
xs = range(len(movies))

# Build bar chart
plt.bar(xs, num_oscars)
plt.ylabel("# of Academy Awards")
plt.title("My Favorite Movies")
plt.xticks(xs, movies)
plt.show()

###
# Bar Charts distribution bins
grades = [83, 95, 91, 87, 70, 0, 85, 82, 100, 67, 73, 77, 0]
decile = lambda grade: grade // 10 * 10
histogram = Counter(decile(grade) for grade in grades)

#plt.bar([x - 4 for x in histogram.keys()],
#        histogram.values(),
#        8)

plt.bar([*histogram.keys()],
        histogram.values(),
       8)

#plt.axis([-5, 105, 0, 5])

plt.xticks([10 * i for i in range(11)])
plt.xlabel("Decile")
plt.ylabel("# of students")
plt.title("Distribution of Exam 1 Grades")
plt.show()

###
# Scatterplots
friends = [70, 65, 72, 63, 71, 64, 60, 64, 67]
minutes = [175, 170, 205, 120, 220, 130, 105, 145, 190]
labels = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i']

plt.scatter(friends, minutes)
plt.axis([0, max(friends)+5, 0, max(minutes)+5])

for label, friend_count, minute_count in zip(labels, friends, minutes):
    plt.annotate(label,
                 xy=(friend_count, minute_count),
                 xytext=(5, -5),
                 textcoords='offset points')

plt.title("Daily Minutes vs. Number of Friends")
plt.xlabel("# of friends")
plt.ylabel("daily minutes spent on the site")
plt.show()