使用带有 knitr 的循环来生成多个 pdf 报告......需要一点帮助才能让我克服困难

首先，我必须承认，我对knitr和可复制分析的概念非常陌生，但我可以看到它在改进我当前的工作流程(包括将大量副本粘贴到word文档中)方面的潜力.

我经常需要按组(本例中为医院)生成多份报告，在每家医院内，可能有许多不同的病房需要我报告结果.之前，我使用循环在R中运行所有绘图和分析，然后开始复制/粘贴工作；然而，在阅读了这篇文章(Can Sweave produce many pdfs automatically?篇)之后，它给了我希望，我可能真的能够跳过许多步骤，直接从R到Rnw/knitr报告.

然而，在try 了一下之后，我发现有一些问题没有完全解决(因为Rnw中的R环境似乎无法识别我试图传递给它的循环变量？？).

   ##  make my data
Hospital <- c(rep("A", 20), rep("B", 20))
Ward <- rep(c(rep("ICU", 10), rep("Medicine", 10)), 2)
Month <- rep(seq(1:10), 4)
Outcomes <- rnorm(40, 20, 5)
df <- data.frame(Hospital, Ward, Month, Outcomes)


##  Here is my current work flow-- produce all plots, but export as png and cut/paste
for(hosp in unique(df$Hospital)){
  subgroup <- df[ df$Hospital == hosp,]
  for(ward in unique(subgroup$Ward)){
    subgroup2 <- subgroup[subgroup$Ward == ward,]
    savename <- paste(hosp, ward)
    plot(subgroup2$Month, subgroup2$Outcomes, type="o", main=paste("Trend plot for", savename))
  }
}
# followed by much copy/pasting


##  Here is what I'm trying to go for using knitr 
library(knitr)
for (hosp in unique(df$Hospital)){
  knit("C:file.path\\testing_loops.Rnw", output=paste('report_', Hospital, '.tex', sep=""))
}

## With the following *Rnw file
## start *.Rnw Code
\documentclass[10pt]{article}
\usepackage[margin=1.15 in]{geometry}
<<loaddata, echo=FALSE, message=FALSE>>=
  Hospital <- c(rep("A", 20), rep("B", 20))
Ward <- rep(c(rep("ICU", 10), rep("Medicine", 10)), 2)
Month <- rep(seq(1:10), 4)
Outcomes <- rnorm(40, 20, 5)
df <- data.frame(Hospital, Ward, Month, Outcomes)
subgroup <- df[ df$Hospital == hosp,]
@

\begin{document}
<<setup, echo=FALSE >>=
  opts_chunk$set(fig.path = paste("test", hosp , sep=""))
@

Some infomative text about hospital \Sexpr{hosp}

<<plots, echo=FALSE >>=
  for(ward in unique(subgroup$Ward)){
    subgroup2 <- subgroup[subgroup$Ward == ward,]
    #     subgroup2 <- subgroup2[ order(subgroup2$Month),]
    savename <- paste(hosp, ward)
    plot(subgroup2$Month, subgroup2$Outcomes, type="o", main=paste("Trend plot for", savename))
  }
@
\end{document}


##  To be then turned into pdf with this
tools::texi2pdf("C:file.path\\report_A.tex", clean = TRUE, quiet = TRUE)

在try 运行knit()代码块后，出现以下错误:

Error in file(con, "w") : invalid 'description' argument

当我查看目录时，*.tex文件将被创建，我可以看到A医院的2个pdf图被生成(B没有)，并且没有医院特定的*.将tex文件编织成pdf.提前感谢您提供的任何帮助！