Convert All Character String Variables in Data Frame to Uppercase in R (Example)
In this tutorial, I’ll illustrate how to change lower case letters in character variables to uppercase in the R programming language.
The content of the post looks as follows:
So now the part you have been waiting for – the example:
Example Data
First, we’ll have to create some data that we can use in the following examples:
data <- data.frame(x1 = letters[1:5], # Create data x2 = 1:5, x3 = c("hello", "hI", "StRiNg", "x", "xXx"), stringsAsFactors = FALSE) data # Show data # x1 x2 x3 # 1 a 1 hello # 2 b 2 hI # 3 c 3 StRiNg # 4 d 4 x # 5 e 5 xXx
The previous output of the RStudio console shows that our example data consists of two character variables and one numeric variable.
Example: Converting Character Columns to Uppercase Using toupper Function
In this Example, I’ll illustrate how to adjust small letters to big letters with the toupper function in R. Consider the following R syntax:
data_new <- data.frame(lapply(data, # Convert data with toupper function function(variables) { if (is.character(variables)) { return(toupper(variables)) } else { return(variables) } }), stringsAsFactors = FALSE) data_new # Show new data # x1 x2 x3 # 1 A 1 HELLO # 2 B 2 HI # 3 C 3 STRING # 4 D 4 X # 5 E 5 XXX
Admittedly, the previous R code is relatively complex. However, as you can see we converted all character strings in our data table to uppercase.
Video, Further Resources & Summary
Have a look at the following video of my YouTube channel. I’m explaining how to capitalize characters based on the R syntax of this tutorial in the video.
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In addition, you may want to read the other tutorials on this homepage. You can find some other articles about the manipulation of character strings below.
- tolower, toupper, casefold & chartr R Functions
- R Capitalize First Letter of Each Word in Character String
- The R Programming Language
At this point you should know how to switch from lowercase to uppercase in R programming. In case you have any additional questions, please let me know in the comments section.
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