soil = read.csv("data/soil_samples.csv", sep = ",", dec = ".")Data in Files
Once you deal with actual data you want to analyse, it is rare that you want to build a data.frame from scratch in your R script or use a predefined example data from within R. Instead, you have some file prepared on your computer e.g. a .csv file you want to get into R. Most likely, this data comes from a spreadsheet application like Excel or Google Sheets that have their own file formats, e.g. a .xlsx file. While it is possible to import .xlsx files into R with external packages, the more elegant way is to use a much simpler file format: comma separated values - .csv.
As the name suggests, a .csv file contains values separated by commas ,:
plotID, soil_ph, soil_temperature, forest_type
1, 5.5, 10, coniferous
2, 5.4, 11, coniferous
3, 6.1, 12, deciduous
Caution with csv files
In Germany, , is used as the decimal point. You will often find csv files where the delimiter is a semicolon ;. Sometimes you will also find files where the separator is a tabstop or four spaces.
To get a .csv file into R, use the read.csv() function. Here you can also specify the dec and sep arguments to the correct symbols for decimal points and separators.