Data Import and Export with readr

Readr is a package that is part of Tidyverse with a range of functions to facilitate the parsing and import of data files into R. It replicates and expands many of the existing function in base R

Importing .csv files

Download my ebird dataset from my github account here: https://github.com/mbtoomey/Biol_7263/blob/main/Data/MBT_ebird.csv?raw=true

Create a “Data” folder in your project and save this files there.

MBT_ebird<-read_csv("Data/MBT_ebird.csv") #read in my ebird csv file from my github account

You can often read files in directly from the web by putting in the web address as the path.

MBT_ebird<-read_csv("https://github.com/mbtoomey/Biol_7263/blob/main/Data/MBT_ebird.csv?raw=true") #read in my ebird csv file from my github account

Readr has a varitey of other functions to import other data formats

• read_tsv() - tab separated data
• read_table() - fixed width files with white space separation
• read_delim() - any delimiter that you specify

Column Names

By default read_csv willl use the first lines as the column names in the resulting tibble. If there are not column names you can omit them:

MBT_ebird<-read_csv("Data/MBT_ebird.csv", col_names = FALSE)

or you can provide a vector of names:

MBT_ebird<-read_csv("Data/MBT_ebird.csv", co_names = c("entry", "list_ID", "common_name")

Parsing

View the imported file

glimpse(MBT_ebird)

You will notice that date and time columns were automatically assigned to the correct data type. Readr uses the following rules, by default to classify data as it is reads in:

• logical: contains only “F”, “T”, “FALSE”, or “TRUE”.
• integer: contains only numeric characters (and -).
• double: contains only valid doubles (including numbers like 4.5e-5).
• number: contains valid doubles with the grouping mark inside.
• time: matches the default time_format.
• date: matches the default date_format.
• date-time: any ISO8601 date.

If none of these rules apply, then the column will stay as a vector of strings.

For specific data import problems these rules can be overridden with specifications within the the function call. More details here: https://readr.tidyverse.org/articles/readr.html

Importing directly from Excel and googlesheets not recommended

There are tools to do this, but I would avoid this if possible as these are likely to be buggy and unpredictable.

• Excel - https://readxl.tidyverse.org/
• GoogleSheets - https://googlesheets4.tidyverse.org/

Exporting data

Readr can export tibbles you create in R is several formats:

• write_delim(x, file, delim = " ") - Write files with any delimiter.
• write_csv(x, file) - Write a comma delimited file.
• write_tsv(x, file) - Write a tab delimited file.