Punctuation notes

From raju


R uses a 1-based indexing scheme (i.e., the
first element of a vector has an index of 1.) This is in contrast to other languages
(i.e., C++, Java, Python) in which the first element has an index of 0.

Demonstrates the usage of i.e. and period inside bracket


Most of the advanced graphing functionality in R is
provided by external packages such as ggplot2,
ggvis, rCharts, and rgl.

Demonstrates using ',' before 'and'.