Hmisc labels including latex math mode

[rapp...@gmail.com]

Thanks for your wonderful package! I have a question though:
I would like to produce latex tables using export2latex. I assigned Hmisc-variable labels so that I don't have to edit the variable names for each table, separately. The labels include latex math mode in $$ and export2latex unfortunately compiles the sign "$" as "\$". Here is a little example:
#####################################################
# assigning Hmisc label includinc math mode in $$
library(Hmisc)
label(mtcars$mpg) <- "[$\\frac{miles}{gallon}$]"

# descriptive table of mpg by am
library(compareGroups)

tab <- createTable(
compareGroups(data = mtcars,
am ~ mpg)
)

# in createTable, the variable name looks fine
tab

# when exported to latex, a \ is inserted before each $
export2latex(tab)
#####################################################
Is there a way out?
Thank you so much for your help!

[compareGroups]

This is a little tricky. The error happens because export2latex function insert "\" scape character before some special characters such as "$". So, you have to remove these "\".

First, call export2latex function and store its result to an object, which will be a text with latex code to generate the descriptive table. 

Then, substitute "\$" by "$".

Below there is an example with a reproducible code in R markdown.

Hope it helps.

---

title: "Example"

author: "Isaac"

output: pdf_document

header-includes:

  - \usepackage{longtable}

  - \usepackage{multicol}

  - \usepackage{multirow}

  - \usepackage{float}

  - \usepackage{lscape} 

---

```{r setup, include=FALSE}

knitr::opts_chunk$set(echo = FALSE, comment="",warning=FALSE,message=FALSE)

```

```{r}

# assigning Hmisc label includinc math mode in $$

library(Hmisc)

label(mtcars$mpg) <- "$\\frac{miles}{gallon}$"

# descriptive table of mpg by am

library(compareGroups)

tab <- createTable(compareGroups(am ~ mpg, data = mtcars))

```

\newpage

```{r,results="hide"}

temp <- export2latex(tab)[[1]]

temp <- sub("\\$\\frac{miles}{gallon}\\$","$\\frac{miles}{gallon}$",temp,fixed=TRUE,perl=FALSE)

```

```{r,results="asis"}

cat(temp)

```