Customize readWorksheet
To get a clear overview about urbanpop.xlsx (view) without having to open up the Excel file, you can execute the following code:
my_book <- loadWorkbook("urbanpop.xlsx")
sheets <- getSheets(my_book)
all <- lapply(sheets, readWorksheet, object = my_book)
str(all)
Suppose we're only interested in urban population data of the years 1968, 1969 and 1970. The data for these years is in the columns 3, 4, and 5 of the second sheet. Only selecting these columns will leave us in the dark about the actual countries the figures belong to.
This exercise is part of the course
Introduction to Importing Data in R
Exercise instructions
- Extend the
readWorksheet()command with thestartColandendColarguments to only import the columns 3, 4, and 5 of the second sheet. urbanpop_selno longer contains information about the countries now. Can you write anotherreadWorksheet()command that imports only the first column from the second sheet? Store the resulting data frame ascountries.- Use
cbind()to paste togethercountriesandurbanpop_sel, in this order. Store the result asselection.
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
# Build connection to urbanpop.xlsx
my_book <- loadWorkbook("urbanpop.xlsx")
# Import columns 3, 4, and 5 from second sheet in my_book: urbanpop_sel
urbanpop_sel <- readWorksheet(my_book, sheet = 2, ___, ___)
# Import first column from second sheet in my_book: countries
countries <- ___
# cbind() urbanpop_sel and countries together: selection
selection <- ___