Quantitative comparisons: bar-charts

Introduction to Data Visualization with Matplotlib

Ariel Rokem

Data Scientist

Olympic medals

,Gold, Silver, Bronze
United States, 137, 52, 67
Germany, 47, 43, 67
Great Britain, 64, 55, 26
Russia, 50, 28, 35
China, 44, 30, 35
France, 20, 55, 21
Australia, 23, 34, 25
Italy, 8, 38, 24
Canada, 4, 4, 61
Japan, 17, 13, 34

Olympic medals: visualizing the data

medals = pd.read_csv('medals_by_country_2016.csv', index_col=0)

fig, ax = plt.subplots()

ax.bar(medals.index, medals["Gold"])
plt.show()

Interlude: rotate the tick labels

fig, ax = plt.subplots()
ax.bar(medals.index, medals["Gold"])

ax.set_xticklabels(medals.index, rotation=90)
ax.set_ylabel("Number of medals")

plt.show()

Olympic medals: visualizing the other medals

fig, ax = plt.subplots
ax.bar(medals.index, medals["Gold"])

ax.bar(medals.index, medals["Silver"], bottom=medals["Gold"])

ax.set_xticklabels(medals.index, rotation=90)
ax.set_ylabel("Number of medals")
plt.show()

Olympic medals: visualizing all three

fig, ax = plt.subplots
ax.bar(medals.index, medals["Gold"])

ax.bar(medals.index, medals["Silver"], bottom=medals["Gold"])

ax.bar(medals.index, medals["Bronze"],
       bottom=medals["Gold"] + medals["Silver"])

ax.set_xticklabels(medals.index, rotation=90)
ax.set_ylabel("Number of medals")
plt.show()

Stacked bar chart

Adding a legend

fig, ax = plt.subplots
ax.bar(medals.index, medals["Gold"])
ax.bar(medals.index, medals["Silver"], bottom=medals["Gold"])
ax.bar(medals.index, medals["Bronze"],
       bottom=medals["Gold"] + medals["Silver"])

ax.set_xticklabels(medals.index, rotation=90)
ax.set_ylabel("Number of medals")

Adding a legend

fig, ax = plt.subplots
ax.bar(medals.index, medals["Gold"], label="Gold")
ax.bar(medals.index, medals["Silver"], bottom=medals["Gold"], 
       label="Silver")
ax.bar(medals.index, medals["Bronze"],
       bottom=medals["Gold"] + medals["Silver"], 
       label="Bronze")

ax.set_xticklabels(medals.index, rotation=90)
ax.set_ylabel("Number of medals")

ax.legend()
plt.show()

Stacked bar chart with legend

Create a bar chart!

Introduction to Data Visualization with Matplotlib