visualize data

AWS/ml/visualize.py

@@ -0,0 +1,162 @@
+import matplotlib.pyplot as plt
+from collections import Counter
+
+def make_chart_simple_line_chart():
+
+    years = [1950, 1960, 1970, 1980, 1990, 2000, 2010]
+    gdp   = [300.2, 543.3, 1075.9, 2862.5, 5979.6, 10289.7, 14958.3]
+
+    # create a line chart, years on x-axis, gdp on y-axis
+    plt.plot(years, gdp, color='green', marker='o', linestyle='solid')
+
+    # add a title
+    plt.title("Nominal GDP")
+
+    # add a label to the y-axis
+    plt.ylabel("Billions of $")
+    plt.show()
+
+
+def make_chart_simple_bar_chart():
+
+    movies = ["Annie Hall", "Ben-Hur", "Casablanca", "Gandhi", "West Side Story"]
+    num_oscars = [5, 11, 3, 8, 10]
+
+    # bars are by default width 0.8, so we'll add 0.1 to the left coordinates
+    # so that each bar is centered
+    xs = [i + 0.1 for i, _ in enumerate(movies)]
+
+    # plot bars with left x-coordinates [xs], heights [num_oscars]
+    plt.bar(xs, num_oscars)
+    plt.ylabel("# of Academy Awards")
+    plt.title("My Favorite Movies")
+
+    # label x-axis with movie names at bar centers
+    plt.xticks([i + 0.5 for i, _ in enumerate(movies)], movies)
+
+    plt.show()
+
+def make_chart_histogram():
+    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()], # shift each bar to the left by 4
+            histogram.values(),                # give each bar its correct height
+            8)                                 # give each bar a width of 8
+    plt.axis([-5, 105, 0, 5])                  # x-axis from -5 to 105,
+                                               # y-axis from 0 to 5
+    plt.xticks([10 * i for i in range(11)])    # x-axis labels at 0, 10, ..., 100
+    plt.xlabel("Decile")
+    plt.ylabel("# of Students")
+    plt.title("Distribution of Exam 1 Grades")
+    plt.show()
+
+def make_chart_misleading_y_axis(mislead=True):
+
+    mentions = [500, 505]
+    years = [2013, 2014]
+
+    plt.bar([2012.6, 2013.6], mentions, 0.8)
+    plt.xticks(years)
+    plt.ylabel("# of times I heard someone say 'data science'")
+
+    # if you don't do this, matplotlib will label the x-axis 0, 1
+    # and then add a +2.013e3 off in the corner (bad matplotlib!)
+    plt.ticklabel_format(useOffset=False)
+
+    if mislead:
+        # misleading y-axis only shows the part above 500
+        plt.axis([2012.5,2014.5,499,506])
+        plt.title("Look at the 'Huge' Increase!")
+    else:
+        plt.axis([2012.5,2014.5,0,550])
+        plt.title("Not So Huge Anymore.")
+    plt.show()
+
+def make_chart_several_line_charts():
+
+    variance     = [1,2,4,8,16,32,64,128,256]
+    bias_squared = [256,128,64,32,16,8,4,2,1]
+    total_error  = [x + y for x, y in zip(variance, bias_squared)]
+
+    xs = range(len(variance))
+
+    # we can make multiple calls to plt.plot
+    # to show multiple series on the same chart
+    plt.plot(xs, variance,     'g-',  label='variance')    # green solid line
+    plt.plot(xs, bias_squared, 'r-.', label='bias^2')      # red dot-dashed line
+    plt.plot(xs, total_error,  'b:',  label='total error') # blue dotted line
+
+    # because we've assigned labels to each series
+    # we can get a legend for free
+    # loc=9 means "top center"
+    plt.legend(loc=9)
+    plt.xlabel("model complexity")
+    plt.title("The Bias-Variance Tradeoff")
+    plt.show()
+
+def make_chart_scatter_plot():
+
+    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)
+
+    # label each point
+    for label, friend_count, minute_count in zip(labels, friends, minutes):
+        plt.annotate(label,
+                     xy=(friend_count, minute_count), # put the label with its point
+                     xytext=(5, -5), # but slightly offset
+                     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()
+
+def make_chart_scatterplot_axes(equal_axes=False):
+
+    test_1_grades = [ 99, 90, 85, 97, 80]
+    test_2_grades = [100, 85, 60, 90, 70]
+
+    plt.scatter(test_1_grades, test_2_grades)
+    plt.xlabel("test 1 grade")
+    plt.ylabel("test 2 grade")
+
+    if equal_axes:
+        plt.title("Axes Are Comparable")
+        plt.axis("equal")
+    else:
+        plt.title("Axes Aren't Comparable")
+
+    plt.show()
+
+def make_chart_pie_chart():
+
+    plt.pie([0.95, 0.05], labels=["Uses pie charts", "Knows better"])
+
+    plt.axis("equal")
+    plt.show()
+
+
+if __name__ == "__main__":
+
+    make_chart_simple_line_chart()
+
+    make_chart_simple_bar_chart()
+
+    make_chart_histogram()
+
+    make_chart_misleading_y_axis(mislead=True)
+
+    make_chart_misleading_y_axis(mislead=False)
+
+    make_chart_several_line_charts()
+
+    make_chart_scatterplot_axes(equal_axes=False)
+
+    make_chart_scatterplot_axes(equal_axes=True)
+
+    make_chart_pie_chart()