Strange behaviour of helpExtract function from SOfun in R 3.1.2

Question

I'm using helpExtract function from SOfun package (written by @Ananda Mahto). The package SOfun can be installed from github using the following command:

devtools::install_github("mrdwab/SOfun")

library(SOfun)

The following command gives in the package document works fine.

textConnection(
  helpExtract(Function = cor, section = "Examples", type = "s_text")
  )

However the same command when using the argument package= fails.

textConnection(
  helpExtract(Function = cor, section = "Examples", type = "s_text", package = "stats")
)

And throws the follow error message:

Error in textConnection(helpExtract(Function = cor, section = "Examples",  : 
  argument 'object' must deparse to a single character string

To include this in `knitr` as child document. As here `\Sexpr{knit_child(textConnection(helpExtract(cor, type = "s_code")), options = list(tidy = FALSE, eval = FALSE))}` for package documentation. — MYaseen208, Jan 09 '15 at 08:22
That error is from `deparse`, but let me see if I can figure anything out. — A5C1D2H2I1M1N2O1R2T1, Jan 09 '15 at 08:29

score 3 · Accepted Answer · answered Jan 09 '15 at 08:53

As mentioned, this is a problem that stems from deparse. I don't have time to dig further to explain the error, but the following works for me:

\documentclass{article}

\begin{document}

<<echo=FALSE>>=
library(SOfun)
x <- helpExtract(Function = cor, section = "Examples", 
                 type = "s_text", package = "stats")
@

\Sexpr{knit_child(textConnection(x),
options = list(tidy = FALSE, eval = FALSE))}

\end{document}

That is, store the output of helpExtract as a variable in a hidden chunk, and use textConnection on that variable.

Strange behaviour of helpExtract function from SOfun in R 3.1.2

1 Answers1