Labeling vector elements with names

The first chunk produces for you vectors from a “real-life” data set, which normally is a data frame/tibble. The Gapminder data set, here loaded from the gapminder R library, shows life expectancy, population, and GDP per capita of many world countries since 1950, from official public sources. We pick random four countries in year 1997 for our exercises.

library(tidyverse)
library(gapminder)
set.seed(12) #this makes "random" the same every time we run this chunk
gap4_1997 <- gapminder %>% dplyr::filter(year == 1997) %>% sample_n(4)
country4 <- gap4_1997$country %>% as.character()  
lifeExp4 <- gap4_1997$lifeExp 
continent4 <- gap4_1997$continent %>% as.character()

Familiarize yourself with the data set (still a data frame):

gap4_1997

… and these are our vectors. They are completely independent of each other now, not remembering that they originate from the same spreadsheet at all!!!

country4

[1] "Nepal"       "Mali"        "Netherlands" "Kenya"      

continent4

[1] "Asia"   "Africa" "Europe" "Africa"

We want the country4 vector to have continent names on its elements. This is what we want:

 Asia        Africa        Europe           Africa 
"Nepal"      "Mali"       "Netherlands"     "Kenya" 

Different ways to do that. When we have names in a vector:

country4

         Asia        Africa        Europe        Africa 
      "Nepal"        "Mali" "Netherlands"       "Kenya" 

If we had to assign the names manually:

named_vec1

         Asia        Africa        Europe        Africa 
      "Nepal"        "Mali" "Netherlands"       "Kenya" 

or

named_vec2

         Asia        Africa        Europe        Africa 
      "Nepal"        "Mali" "Netherlands"       "Kenya" 

named_vec3

Error: object 'named_vec3' not found