Processing R markdown (Rmd) documents with Eclipse/StatET external tools requires a different setup than processing ‘regular’ knitr documents (Rnw). I was having problems getting the whole rmarkdown -> pandoc workflow working on Eclipse, but the following fix seems to have resolved it, and I can generate Word or HTML documents from a single .Rmd file with a YAML header (see image below).
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For starters, I open the Run > External Tools > External Tools Configurations window. The Rmarkdown document is considered a type of Wikitext, so create a new Wikitext + R Document Processing entry. To do that, hit the little blank-page-with-a-plus icon found in the upper left corner of the window, above where it says “type filter text”.
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Enter a name for this configuration in the Name field (where it says knitr_RMD_yaml in my image above). I then used the Load Preset/Example menu in the upper right to choose the “Auto (YAML) using RMarkdown, single-step” option. This processes your .Rmd document directly using the rmarkdown::render() function, skipping over a separate knitr::knit() step, but the output should look the same.
Next go to the “2) Produce Output” tab (you are skipping over the “1) R-Weave” tab because you chose the 1-step process). By default the entry in the File field here was causing errors for me. The change is pictured below, so that the File entry reads "${file_name_base:${source_file_path}}.${out_file_ext}"
. This change allowed my setup to actually find the .Rmd and output .md files successfully, so that the .md document could then be passed on to pandoc.
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This all assumes that you’ve previously downloaded and installed pandoc so that it can be found on the Windows system $PATH.