## Learning R

·         Examine the R help file

o    start R and type 'help.start()'

o    explore the html help to learn what’s available there

o    check out "An Introduction to R" (access this from html help menu)

·         Work through "The R Guide" (http://cran.fhcrc.org/doc/contrib/Owen-TheRGuide.pdf). We won't do much with statistics in this course, so section 7 of the guide is less important for this course. But, we will use much of the material that is presented in this guide, including much of the material covered in section 8. There are many very useful manuals available from the CRAN site (look under Documentation). I chose this guide as its focus aligns well with what we'll do this semester with R.

·         Provide R code that

o    stores the values 0.90, 0.93, 0.8, 0.95, and 0.91 in a vector named "s"; calculates the number of items stored in "s"; calculates the mean of the values in "s"; calculates the cumulative product of the values in "s"; and plots the values of "s" on the vertical axis against the values for the years 1993, 1994, ..., 1997 on the horizontal axis. ·         generates 500 random numbers from a normal distribution with a mean of 15 and a standard deviation of 2.3 (hint: type "?rnorm"); stores the values in a vector named “x”; plots a histogram of the values in “x”; & calculates the mean & sd for the values in “x”

·         creates a function called “mls” that calculates mean life span based on any given constant survival rate implements that function on a sequence of survival rates ranging from 0.20 to 0.95 by steps of 0.05, and produces 2 columns of output with column 1 being the survival rates and column 2 being the associated mean life spans.

·         explain what running "rbinom(1,25,0.5)" is accomplishing

·         explain what running "rbinom(100,25,0.5)" is accomplishing

·         explain what running "mean(rbinom(100,25,0.5))" is accomplishing