Interfacing with R

R provides a datasets package that contains sample datasets. The morley dataset has data from measurements of the speed of light made in 1879. The speed of light is a fundamental physical constant and its value is currently known very precisely. The data is described at http://stat.ethz.ch/R-manual/R-devel/library/datasets/html/morley.html. The speed of light value can be found in the scipy.constants module. The R data is stored in an R dataframe with three columns:

• The experiment number from one to five
• The run number with twenty runs per experiment, bringing the total measurements to 100
• The measured speed of light in kilometers per second with 299,000 subtracted

The rpy2.robjects.r() function executes R code in a Python environment. Load the data as follows:

ro.r('data(morley)')

The pandas library provides an R interface via the pandas.rpy.common module. Load the data into a pandas DataFrame as follows:

df = com.load_data('morley')

Let's group the...