library(tidyr)
library(dplyr)
## 
## Attaching package: 'dplyr'
## The following objects are masked from 'package:stats':
## 
##     filter, lag
## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union
library(ggplot2)
## Warning: package 'ggplot2' was built under R version 3.5.3
library(stringr)

Read the information from your .CSV file into R, and use tidyr and dplyr as needed to tidy and transform your data.

dataset1 <- read.csv("https://raw.githubusercontent.com/Zchen116/assignment-2/master/unicef-u5mr.csv")
head(dataset1)
##         CountryName U5MR.1950 U5MR.1951 U5MR.1952 U5MR.1953 U5MR.1954
## 1       Afghanistan        NA        NA        NA        NA        NA
## 2           Albania        NA        NA        NA        NA        NA
## 3           Algeria        NA        NA        NA        NA       251
## 4           Andorra        NA        NA        NA        NA        NA
## 5            Angola        NA        NA        NA        NA        NA
## 6 Antigua & Barbuda        NA        NA        NA        NA        NA
##   U5MR.1955 U5MR.1956 U5MR.1957 U5MR.1958 U5MR.1959 U5MR.1960 U5MR.1961
## 1        NA        NA        NA        NA        NA        NA     356.5
## 2        NA        NA        NA        NA        NA        NA        NA
## 3     249.9       249       248     247.5     246.7     246.3     246.1
## 4        NA        NA        NA        NA        NA        NA        NA
## 5        NA        NA        NA        NA        NA        NA        NA
## 6        NA        NA        NA        NA        NA        NA        NA
##   U5MR.1962 U5MR.1963 U5MR.1964 U5MR.1965 U5MR.1966 U5MR.1967 U5MR.1968
## 1     350.6     345.0     339.7     334.1     328.7     323.3     318.1
## 2        NA        NA        NA        NA        NA        NA        NA
## 3     246.2     246.8     247.4     248.2     248.7     248.4     247.4
## 4        NA        NA        NA        NA        NA        NA        NA
## 5        NA        NA        NA        NA        NA        NA        NA
## 6        NA        NA        NA        NA        NA        NA        NA
##   U5MR.1969 U5MR.1970 U5MR.1971 U5MR.1972 U5MR.1973 U5MR.1974 U5MR.1975
## 1     313.0     307.8     302.1     296.4     290.8     284.9     279.4
## 2        NA        NA        NA        NA        NA        NA        NA
## 3     245.3     241.7     236.5     230.0     222.5     214.2     205.0
## 4        NA        NA        NA        NA        NA        NA        NA
## 5        NA        NA        NA        NA        NA        NA        NA
## 6        NA        NA        NA        NA        NA        NA        NA
##   U5MR.1976 U5MR.1977 U5MR.1978 U5MR.1979 U5MR.1980 U5MR.1981 U5MR.1982
## 1     273.6     267.8     261.6     255.5     249.1     242.7     236.2
## 2        NA        NA      91.1      84.7      78.6      73.0      67.8
## 3     195.2     184.9     173.8     161.8     148.1     132.5     115.8
## 4        NA        NA        NA        NA        NA        NA        NA
## 5        NA        NA        NA        NA     234.1     232.8     231.5
## 6        NA        NA        NA        NA        NA        NA        NA
##   U5MR.1983 U5MR.1984 U5MR.1985 U5MR.1986 U5MR.1987 U5MR.1988 U5MR.1989
## 1     229.7     222.9     216.0     209.2     202.1     195.0     187.8
## 2      62.8      58.3      54.3      50.7      47.6      44.9      42.5
## 3      99.2      83.8      71.2      61.9      55.4      51.2      48.5
## 4        NA        NA        NA        NA        NA        NA        NA
## 5     230.2     229.1     228.3     227.5     226.9     226.5     226.2
## 6        NA        NA        NA        NA        NA        NA        NA
##   U5MR.1990 U5MR.1991 U5MR.1992 U5MR.1993 U5MR.1994 U5MR.1995 U5MR.1996
## 1     181.0     174.2     167.8     162.0     156.8     152.3     148.6
## 2      40.6      38.8      37.3      36.0      34.6      33.2      31.8
## 3      46.8      45.7      44.9      44.1      43.3      42.5      41.8
## 4       8.5       7.9       7.4       6.9       6.4       6.0       5.7
## 5     226.0     225.9     226.0     225.8     225.5     224.8     224.0
## 6      25.5      24.2      23.1      21.9      20.8      19.7      18.8
##   U5MR.1997 U5MR.1998 U5MR.1999 U5MR.2000 U5MR.2001 U5MR.2002 U5MR.2003
## 1     145.5     142.6     139.9     137.0     133.8     130.3     126.8
## 2      30.3      28.9      27.5      26.2      24.9      23.6      22.5
## 3      41.1      40.6      40.2      39.7      38.9      37.8      36.5
## 4       5.3       5.0       4.8       4.6       4.4       4.2       4.1
## 5     222.6     220.8     218.9     216.7     214.1     211.7     209.2
## 6      17.9      17.0      16.2      15.5      14.8      14.1      13.5
##   U5MR.2004 U5MR.2005 U5MR.2006 U5MR.2007 U5MR.2008 U5MR.2009 U5MR.2010
## 1     123.2     119.6     116.3     113.2     110.4     107.6     105.0
## 2      21.5      20.5      19.5      18.7      17.9      17.3      16.6
## 3      35.1      33.6      32.1      30.7      29.4      28.3      27.3
## 4       4.0       3.9       3.7       3.6       3.5       3.4       3.3
## 5     206.7     203.9     200.5     196.4     192.0     187.3     182.5
## 6      12.9      12.4      11.8      11.3      10.9      10.4       9.9
##   U5MR.2011 U5MR.2012 U5MR.2013 U5MR.2014 U5MR.2015
## 1     102.3      99.5      96.7      93.9      91.1
## 2      16.0      15.5      14.9      14.4      14.0
## 3      26.6      26.1      25.8      25.6      25.5
## 4       3.2       3.1       3.0       2.9       2.8
## 5     177.3     172.2     167.1     162.2     156.9
## 6       9.5       9.1       8.7       8.4       8.1

check the names from dataset 1

names(dataset1)
##  [1] "CountryName" "U5MR.1950"   "U5MR.1951"   "U5MR.1952"   "U5MR.1953"  
##  [6] "U5MR.1954"   "U5MR.1955"   "U5MR.1956"   "U5MR.1957"   "U5MR.1958"  
## [11] "U5MR.1959"   "U5MR.1960"   "U5MR.1961"   "U5MR.1962"   "U5MR.1963"  
## [16] "U5MR.1964"   "U5MR.1965"   "U5MR.1966"   "U5MR.1967"   "U5MR.1968"  
## [21] "U5MR.1969"   "U5MR.1970"   "U5MR.1971"   "U5MR.1972"   "U5MR.1973"  
## [26] "U5MR.1974"   "U5MR.1975"   "U5MR.1976"   "U5MR.1977"   "U5MR.1978"  
## [31] "U5MR.1979"   "U5MR.1980"   "U5MR.1981"   "U5MR.1982"   "U5MR.1983"  
## [36] "U5MR.1984"   "U5MR.1985"   "U5MR.1986"   "U5MR.1987"   "U5MR.1988"  
## [41] "U5MR.1989"   "U5MR.1990"   "U5MR.1991"   "U5MR.1992"   "U5MR.1993"  
## [46] "U5MR.1994"   "U5MR.1995"   "U5MR.1996"   "U5MR.1997"   "U5MR.1998"  
## [51] "U5MR.1999"   "U5MR.2000"   "U5MR.2001"   "U5MR.2002"   "U5MR.2003"  
## [56] "U5MR.2004"   "U5MR.2005"   "U5MR.2006"   "U5MR.2007"   "U5MR.2008"  
## [61] "U5MR.2009"   "U5MR.2010"   "U5MR.2011"   "U5MR.2012"   "U5MR.2013"  
## [66] "U5MR.2014"   "U5MR.2015"

check data types from dataset 1

sapply(dataset1,class)
## CountryName   U5MR.1950   U5MR.1951   U5MR.1952   U5MR.1953   U5MR.1954 
##    "factor"   "numeric"   "numeric"   "numeric"   "numeric"   "numeric" 
##   U5MR.1955   U5MR.1956   U5MR.1957   U5MR.1958   U5MR.1959   U5MR.1960 
##   "numeric"   "numeric"   "numeric"   "numeric"   "numeric"   "numeric" 
##   U5MR.1961   U5MR.1962   U5MR.1963   U5MR.1964   U5MR.1965   U5MR.1966 
##   "numeric"   "numeric"   "numeric"   "numeric"   "numeric"   "numeric" 
##   U5MR.1967   U5MR.1968   U5MR.1969   U5MR.1970   U5MR.1971   U5MR.1972 
##   "numeric"   "numeric"   "numeric"   "numeric"   "numeric"   "numeric" 
##   U5MR.1973   U5MR.1974   U5MR.1975   U5MR.1976   U5MR.1977   U5MR.1978 
##   "numeric"   "numeric"   "numeric"   "numeric"   "numeric"   "numeric" 
##   U5MR.1979   U5MR.1980   U5MR.1981   U5MR.1982   U5MR.1983   U5MR.1984 
##   "numeric"   "numeric"   "numeric"   "numeric"   "numeric"   "numeric" 
##   U5MR.1985   U5MR.1986   U5MR.1987   U5MR.1988   U5MR.1989   U5MR.1990 
##   "numeric"   "numeric"   "numeric"   "numeric"   "numeric"   "numeric" 
##   U5MR.1991   U5MR.1992   U5MR.1993   U5MR.1994   U5MR.1995   U5MR.1996 
##   "numeric"   "numeric"   "numeric"   "numeric"   "numeric"   "numeric" 
##   U5MR.1997   U5MR.1998   U5MR.1999   U5MR.2000   U5MR.2001   U5MR.2002 
##   "numeric"   "numeric"   "numeric"   "numeric"   "numeric"   "numeric" 
##   U5MR.2003   U5MR.2004   U5MR.2005   U5MR.2006   U5MR.2007   U5MR.2008 
##   "numeric"   "numeric"   "numeric"   "numeric"   "numeric"   "numeric" 
##   U5MR.2009   U5MR.2010   U5MR.2011   U5MR.2012   U5MR.2013   U5MR.2014 
##   "numeric"   "numeric"   "numeric"   "numeric"   "numeric"   "numeric" 
##   U5MR.2015 
##   "numeric"

Gather columns of Year, Value, and Country name into a new pair of variables

dataset1_tidy <- gather(dataset1, Year,Value,-CountryName)
head(dataset1_tidy)
##         CountryName      Year Value
## 1       Afghanistan U5MR.1950    NA
## 2           Albania U5MR.1950    NA
## 3           Algeria U5MR.1950    NA
## 4           Andorra U5MR.1950    NA
## 5            Angola U5MR.1950    NA
## 6 Antigua & Barbuda U5MR.1950    NA

Convert value to numeric

dataset1_tidy$Year <- str_extract(dataset1_tidy$Year,"\\d+$")
dataset1_tidy$Year <- as.numeric(dataset1_tidy$Year)

Analysis data by ggplot graph

dataset1_tidy %>%
    group_by(Year)%>%
    summarise(avg = mean(Value, na.rm = TRUE)) %>%
    ggplot(aes(Year,avg))+geom_line()+theme_classic()+ggtitle("Under-Five Child Mortality Over The Years")

dataset1_tidy %>%
    filter(Year == min(Year))%>%
    arrange(Value)%>%
    head()
##   CountryName Year Value
## 1      Sweden 1950  27.1
## 2   Australia 1950  31.6
## 3 Netherlands 1950  31.9
## 4      Norway 1950  32.8
## 5     Denmark 1950  34.1
## 6 New Zealand 1950  35.5
dataset1_tidy %>%
    filter(Year == min(Year))%>%
    arrange(-Value)%>%
    head()
##    CountryName Year Value
## 1 Burkina Faso 1950 389.7
## 2         Iraq 1950 364.3
## 3        Benin 1950 348.2
## 4      Senegal 1950 346.2
## 5         Togo 1950 324.4
## 6   Mauritania 1950 316.4

Conclusion: From the graph we can know that child mortality has ben decreased years by years. African countries has the highest child mortality and developed countries lowest child mortality even on 1950.