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Reshape wide data in R: Converting two rows into columns


How do I transpose this dataset in R? See below:

I downloaded a dataset that looks like this (the dates go backward from 2016 - 1975):

           V1               V2               V3               V4               V5
1                         2016             2016             2016             2015
4     Country       Both-sexes             Male           Female       Both-sexes
5 Afghanistan 23.4 [22.0-24.8] 22.6 [20.1-25.1] 24.1 [23.0-25.3] 23.3 [21.9-24.6]
6     Albania 26.7 [25.8-27.5] 27.0 [25.8-28.2] 26.3 [25.0-27.6] 26.6 [25.8-27.4]
7     Algeria 25.5 [24.5-26.5] 24.7 [23.4-26.1] 26.4 [24.9-27.8] 25.5 [24.5-26.4]
8     Andorra 26.7 [24.6-28.7] 27.3 [24.8-29.8] 26.1 [22.8-29.5] 26.7 [24.7-28.7]

I need to make the year and sex rows (currently numbered rows 1 & 4) into columns. Here's what I want:

1 Country Year Sex Rate 2 Afghanistan 2016 Both-sexes 23.4 3 Afghanistan 2016 Male 22.6 3 Afghanistan 2016 Female 24.1 4 Afghanistan 2015 Both-sexes 23.3

...and the rows continue on through all of the years for all of the countries in the dataset.

Here's what I have done trying to get there:

cfile <- read.csv(file= "countries-BMI.csv", header = F)


#removed second two rows that have unnecessary info
countries_data <- cfile[-c(2,3), ]

molten_countries_data <- melt(countries_data, id=c("V1"))

.and here's my result - head(molten_countries_data):

           V1 variable            value
1                   V2             2016
2     Country       V2       Both-sexes
3 Afghanistan       V2 23.4 [22.0-24.8]
4     Albania       V2 26.7 [25.8-27.5]
5     Algeria       V2 25.5 [24.5-26.5]
6     Andorra       V2 26.7 [24.6-28.7]

Not what I wanted! Please help.


Solution

  • I figured it out thanks to the tip from @Dave2e to merge the first 2 rows first. Here's what I ended up doing:

    library(reshape2)
    library(tidyr)
    
    #load data frame without first two rows
    cdata <- read.csv("countries-BMI.csv", skip = 2, header = F)
    
    #create header by combining top two rows
    headers <- read.csv("countries-BMI.csv", nrows=2, header=FALSE)
    headers_names <- sapply(headers,paste,collapse="_")
    
    #add the new header to data frame
    names(cdata) <- headers_names
    
    #transpose the "wide data" to make it tidy/long
    longdata <- melt(cdata, id.vars = c("_Country"))
    
    #separate the year and sex columns
    countriesBMI2 <- separate(data = longdata, col = variable, into = c("Year", "Sex"), sep = "_")
    

    My result: head(countriesBMI2)

                 _Country Year        Sex            value
    1         Afghanistan 2016 Both-sexes 23.4 [22.0-24.8]
    2             Albania 2016 Both-sexes 26.7 [25.8-27.5]
    3             Algeria 2016 Both-sexes 25.5 [24.5-26.5]
    4             Andorra 2016 Both-sexes 26.7 [24.6-28.7]
    5              Angola 2016 Both-sexes 23.3 [21.2-25.6]
    6 Antigua and Barbuda 2016 Both-sexes 26.7 [24.6-28.8]