How to include an external code file in rmakdown to output in pdf with sintax highlight

Question

My question is inspired from this one. However, the difference is that my output is PDF.

I have a C++ code saved in an external file. I want to print it into a r markdown PDF with syntax highlight.

My example.cpp code, which is in fact a TMB code:

// Fitting Bivariate Gaussian distribution.
#include <TMB.hpp>
template<class Type>
Type objective_function<Type>::operator() ()
{
  using namespace density;
  DATA_MATRIX(Y);
  PARAMETER_VECTOR(rho);
  PARAMETER_VECTOR(sigma);
  vector<Type> rho_temp(1);
  rho_temp = rho;
  vector<Type> sigma_temp(2);
  sigma_temp = sigma;
  Type res;
  for(int i = 0; i < 50; i++)
    res += VECSCALE(UNSTRUCTURED_CORR(rho_temp), sigma_temp)(Y.row(i));
  return res;
}

Minimal code:

---
title: "Code to PDF"
output: beamer_presentation
safe-columns: true # enables special latex macros for columns
header-includes:
- \usepackage{listings}
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = FALSE)
setwd("/home/guilherme/Google Drive/Mestrado/dissertacao/TMB/Presentation")
```

## Slide1

\lstinputlisting[language=C++]{example.cpp}

result in the slide:

Is there a better way to do this highlighting?

Effloresce

You could probably simplify your command with \lstinputlisting[language=C++]{example.cpp}. Maybe with some ```{latex}... around it. Can you make a minimal reproducible example to test? – Kubiak

I just did it with your suggestion – Effloresce

Answer 1

You can run a lot of engines in Rmarkdown. You can find them here.

In general case:

My C++ archive, which I named as 'mycpp.cpp':

# include <iostream>

class Passaro                       // classe base
{
public:
   virtual void MostraNome()
   {
      std::cout << "um passaro";
   }
   virtual ~Passaro() {}
};

class Cisne: public Passaro         // Cisne é um pássaro
{
public:
   void MostraNome()
   {
      std::cout << "um cisne";        // sobrecarrega a função virtual
   }
};

int main()
{
   Passaro* passaro = new Cisne;

   passaro->MostraNome();            // produz na saída "um cisne", e não "um pássaro"

   delete passaro;
}

My Rmd archive:

---
title: "Code to PDF"
output:
  pdf_document
---

# Cats are nicer than dogs

```{Rcpp, code=readLines('mycpp.cpp')}
```

Output:

Especific to your case, try this:

---
title: "Code to PDF"
output: beamer_presentation
safe-columns: true # enables special latex macros for columns
header-includes:
- \usepackage{listings}
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = FALSE)
setwd("/home/guilherme/Google Drive/Mestrado/dissertacao/TMB/Presentation")
```

## Slide1

```{Rcpp, eval = FALSE, echo = TRUE, code=readLines('example.cpp')}
```

Ravenna