STAT 545A Homework 2

Objectives

This is a warm-up exercise for using R Markdown in making reports. To this end we have used a Gapminder Dataset.

Data Loading

The following part, loads the data from the input URL.

gdURL <- "http://www.stat.ubc.ca/~jenny/notOcto/STAT545A/examples/gapminder/data/gapminderDataFiveYear.txt"
gDat <- read.delim(file = gdURL)

The number of observation is obtained by counting the total number of rows in the data.

nrow(gDat)
## [1] 1704

There are several variables, in the data set,describing these observations

colnames(gDat)
## [1] "country"   "year"      "pop"       "continent" "lifeExp"   "gdpPercap"

Some very basic descriptive statistics for the data is obtained as follows

summary(gDat)
##         country          year           pop              continent  
##  Afghanistan:  12   Min.   :1952   Min.   :6.00e+04   Africa  :624  
##  Albania    :  12   1st Qu.:1966   1st Qu.:2.79e+06   Americas:300  
##  Algeria    :  12   Median :1980   Median :7.02e+06   Asia    :396  
##  Angola     :  12   Mean   :1980   Mean   :2.96e+07   Europe  :360  
##  Argentina  :  12   3rd Qu.:1993   3rd Qu.:1.96e+07   Oceania : 24  
##  Australia  :  12   Max.   :2007   Max.   :1.32e+09                 
##  (Other)    :1632                                                   
##     lifeExp       gdpPercap     
##  Min.   :23.6   Min.   :   241  
##  1st Qu.:48.2   1st Qu.:  1202  
##  Median :60.7   Median :  3532  
##  Mean   :59.5   Mean   :  7215  
##  3rd Qu.:70.8   3rd Qu.:  9325  
##  Max.   :82.6   Max.   :113523  
## 

To Fight or Not To Fight

In this part we see the trend in per capita GDP for two neighboring countries : Iran and Iraq from 1952 to 2007:

library(lattice)
xyplot(gdpPercap ~ year, gDat, subset = (country == "Iraq" | country == "Iran"), 
    group = country, type = c("p", "spline"), key = list(lines = Rows(trellis.par.get("superpose.line"), 
        c(5:6)), text = list(lab = c("Iran", "Iraq")), columns = 2, title = "Per Capita GDP in two neighboring countries"))

plot of chunk unnamed-chunk-5

As we see, a big decline in Per Capita GDP for Iran occured close to First Persian Gulf (Iran-Iraq) War (1980-1988). Afterwards, Iran has started to grow in Per Capita GDP, however Iraq continues the decline during and even after the second Persian Gulf war (1990-1991). Iraq's second decline in GDP per capita started during the next war (2003).