Table of multiple lm() models using apsrtable in Rmarkdown

Question

Goal

Present the results of multiple models, created using the lm() function, together in a nicely-formatted table. This table will be generated in a .Rmd file and output to a PDF document.

Proposed Solution

In Reproducible Research with R and RStudio, there is an example using the apsrtable() function to display multiple models side-by-side. This book provides the following code (p. 173-174):

Code

\begin{table}
    \caption{Example Nested Estimates Table with \emph{aprstable}}
    \label{BasicApsrTableExample}
        \begin{center}
<<results= asis , echo=FALSE>>=
# Load apsrtable package
library(apsrtable)
# Create nested regression model table
apsrtable(M1, M2, M3, M4, M5, Sweave = TRUE,
      stars = "default")
@
       \end{center}
\end{table}

where the models M1 ... M5 are created in chunks using M2 <- lm(Examination ~ Education + Agriculture, data = swiss).

Output

Below is a screen grab of the results, as reported in the book. This is exactly the table I want to create in my .Rmd file and output to a PDF document.

Issues

Attempt 1 When I try to use this code inside a code chunk—as shown below—and the output to a PDF, I get a an error message: Error: $ operator is invalid for atomic vectors

```{r}
t.model2 = xtable(model2,label = NULL)
t.model3 = xtable(model3,label = NULL)

library(apsrtable)

apsrtable(t.model2, t.model3, Sweave = TRUE, stars = "default")
```

Attempt 2 When I use the above code outside a code chunk, the .Rmd file outputs to PDF, but displays the following:

Questions

My Questions

• Why are these attempts failing?
• What is the correct way to use the apsrtable function inside a .Rmd?
• Will this method work to ouput this .Rmd file to PDF?

Related Stack Overflow Questions

• Tools for making latex tables in R

• Include apsrtable (or stargazer) output in an Rmd file

• Combining several regression tables into one for use in xtable with Sweave in R

Answer 1

You need to take care of the following two things:

• Chunk option results='asis'
• \usepackage{dcolumn} must be in the preamble as stated in the help file.

Another option would be the stargazer package, which allows to knit not only to PDF but to HTML as well (see screenshot).

---
title: "stargazer"
author: "hplieninger"
date: "3 August 2018"
output: pdf_document
header-includes:
    - \usepackage{dcolumn}
---

```{r}
m1 <- lm(Fertility ~ Education , data = swiss)
m2 <- lm(Fertility ~ Education + Agriculture, data = swiss)
m3 <- lm(Fertility ~ . , data = swiss)
```

```{r, results='asis'}
apsrtable::apsrtable(m1, m2, m3, Sweave = TRUE)
```

```{r, results='asis'}
# If output: pdf_document
stargazer::stargazer(m1, m2, m3)
# If output: html_document
# stargazer::stargazer(m1, m2, m3, type = "html")
```