Using kable() for Printing Tables in R Markdown Documents

Printing Tables in the Plot Window or Markdown Using kable?

When working with data visualization and reporting, it’s essential to present your findings in an organized and clear manner. One common approach is to use tables to display data points, model performance metrics, or other relevant information. In this article, we’ll explore how to print tables in the plot window or markdown using the kable() function from the kableExtra package.

Background

The kable() function is part of the kableExtra package, which extends the functionality of the kable() function in the knitr package. The kable() function allows you to create tables with various formatting options and print them directly into your R Markdown or HTML documents.

Understanding kable()

The kable() function takes several arguments that control its behavior, including:

data: This is the input data for which you want to create a table.
format: This argument determines the format of the table. Possible values include "latex", "html", "pipe", "simple", and "rst" (R Markdown).
escape: If TRUE (default), HTML characters in the data will be escaped; if FALSE, they won’t.
**align`: This argument specifies whether to align the columns or not.

Here is an example of how you can use kable():

# Load required libraries

library(knitr)
library(kableExtra)

# Create a sample data frame

set.seed(123)
df <- data.frame(
    "Name" = c("John", "Anna", "Peter", "Linda"),
    "Age" = c(28, 24, 35, 32),
    "City" = c("New York", "Paris", "Tokyo", "Sydney")
)

# Print the data using kable()

print(kable(df))

Using Results = “asis”

One common use case for kable() is when you want to print tables in a Markdown document. In this scenario, you can specify the results argument as "asis".

# Load required libraries

library(knitr)
library(kableExtra)

# Create a sample data frame

set.seed(123)
df <- data.frame(
    "Name" = c("John", "Anna", "Peter", "Linda"),
    "Age" = c(28, 24, 35, 32),
    "City" = c("New York", "Paris", "Tokyo", "Sydney")
)

# Print the data using kable() with results = "asis"

print(kable(df, results = "asis"))

Specifying Format

The format argument determines the format of the table. Possible values include "latex", "html", "pipe", "simple", and "rst".

Here is an example of how you can use different formats:

# Load required libraries

library(knitr)
library(kableExtra)

# Create a sample data frame

set.seed(123)
df <- data.frame(
    "Name" = c("John", "Anna", "Peter", "Linda"),
    "Age" = c(28, 24, 35, 32),
    "City" = c("New York", "Paris", "Tokyo", "Sydney")
)

# Print the data using kable() with different formats

print(kable(df)) # default format: html
print(kable(df, format = "latex")) # latex format
print(kable(df, format = "pipe")) # pipe format

Changing the Format

You can change the format argument when calling kable() to produce tables in different formats. Here is an example of how you can use a function to return a character string:

# Load required libraries

library(knitr)
library(knitr)

# Create a sample data frame

set.seed(123)
df <- data.frame(
    "Name" = c("John", "Anna", "Peter", "Linda"),
    "Age" = c(28, 24, 35, 32),
    "City" = c("New York", "Paris", "Tokyo", "Sydney")
)

# Create a function to return the format

get_format <- function() {
    # choose which table format you want
    format <- "latex"
    # if you have multiple options, you could use a loop here
    # see example above for how to set kable.table.format
    return(format)
}

# Use the function when calling kable()

print(kable(df, get_format()))

Printing Tables in Pipe Format

You can print tables directly into HTML documents by setting the format argument of the kable() function as "pipe":

# Load required libraries

library(knitr)
library(knitr)

# Create a sample data frame

set.seed(123)
df <- data.frame(
    "Name" = c("John", "Anna", "Peter", "Linda"),
    "Age" = c(28, 24, 35, 32),
    "City" = c("New York", "Paris", "Tokyo", "Sydney")
)

# Print the data using kable() in pipe format

print(kable(df, format = "pipe"))

Using Simple Format for Pandoc’s Simple Tables

Pandoc provides several different formats to create simple tables:

Markdown
MediaWiki

Here is an example of how you can use simple to generate a simple table that Pandoc will render correctly.

# Load required libraries

library(knitr)
library(knitr)

# Create a sample data frame

set.seed(123)
df <- data.frame(
    "Name" = c("John", "Anna", "Peter", "Linda"),
    "Age" = c(28, 24, 35, 32),
    "City" = c("New York", "Paris", "Tokyo", "Sydney")
)

# Print the data using kable() in simple format

print(kable(df, format = "simple"))

Using R Markdown for Printing Tables

R Markdown provides several ways to print tables directly into your document:

Knitr
kable() function

Here is an example of how you can use knitr and the kable() function to create a table.

# Load required libraries

library(knitr)

# Create a sample data frame

set.seed(123)
df <- data.frame(
    "Name" = c("John", "Anna", "Peter", "Linda"),
    "Age" = c(28, 24, 35, 32),
    "City" = c("New York", "Paris", "Tokyo", "Sydney")
)

# Print the data using knitr and kable()

print(knitr::kable(df))

Printing Tables in LaTeX Format

You can print tables directly into your document by setting the format argument of the kable() function as "latex":

# Load required libraries

library(knitr)
library(knitr)

# Create a sample data frame

set.seed(123)
df <- data.frame(
    "Name" = c("John", "Anna", "Peter", "Linda"),
    "Age" = c(28, 24, 35, 32),
    "City" = c("New York", "Paris", "Tokyo", "Sydney")
)

# Print the data using kable() in latex format

print(knitr::kable(df, format = "latex"))

Conclusion

Printing tables directly into your document can help present your findings in an organized and clear manner. With kable() from the kableExtra package, you can create tables with various formatting options.

You can use several arguments to control the behavior of kable(), including results = "asis" for printing tables in Markdown format, format for specifying the table format, and get_format() for dynamically choosing a format.

By following these steps, you can easily print tables directly into your document, helping to present your findings in an organized and clear manner.

Last modified on 2023-06-09