PDF/HTML graphics

graphics.R

include_graphics <- function(path, image_opts = NULL, pdf_opts = NULL) {

  sys_call <- sys.calls()
  produce_pdf <- sapply(c('exams2pdf', 'exams2nops'),
                        function(x) any(grepl(x, sapply(sys_call, deparse))))

  if (any(produce_pdf)){
    path_to_pdf <- paste0(tools::file_path_sans_ext(path), '.pdf')
    if (file.exists(path_to_pdf)){
      pdf_options <- if (!is.null(pdf_opts)) {
        paste(paste(names(pdf_opts), pdf_opts, sep = '='), collapse = ', ')
      }
      cat('\\includegraphics[', pdf_options, ']{', path_to_pdf ,'}', sep = '')
    }
  } else {

    alt <- if (!is.null(image_opts$alt)) image_opts$alt else ''
    width <- if (!is.null(image_opts$width))
        sprintf('{width=%s}', image_opts$width) else ''
    cat(sprintf('![%s](%s)%s', alt, path, width))
  }
}

test.Rmd

```{r, echo=FALSE, results='asis'}
examtools::include_graphics('gbpusd.png', 
                            pdf_opts = list(width = '0.6\\textwidth'),
                            image_opts = list(width = '12cm'))
```