Comparing percentiles to ECDF
To see how the percentiles relate to the ECDF, you will plot the percentiles of Iris versicolor petal lengths you calculated in the last exercise on the ECDF plot you generated in chapter 1. The percentile variables from the previous exercise are available in the workspace as ptiles_vers
and percentiles
.
Note that to ensure the Y-axis of the ECDF plot remains between 0 and 1, you will need to rescale the percentiles
array accordingly - in this case, dividing it by 100.
This exercise is part of the course
Statistical Thinking in Python (Part 1)
Exercise instructions
- Plot the percentiles as red diamonds on the ECDF. Pass the x and y co-ordinates -
ptiles_vers
andpercentiles/100
- as positional arguments and specify themarker='D'
,color='red'
andlinestyle='none'
keyword arguments. The argument for the y-axis -percentiles/100
has been specified for you. - Display the plot.
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
# Plot the ECDF
_ = plt.plot(x_vers, y_vers, '.')
_ = plt.xlabel('petal length (cm)')
_ = plt.ylabel('ECDF')
# Overlay percentiles as red diamonds.
_ = plt.plot(____, percentiles/100, ____='D', ____='red',
____=____)
# Show the plot