how to create a loop that includes both a code chunk and text with knitr in R

问题

I am trying to figure out how to create a loop that inserts some text into the rmarkdown file, and then produces the graph or table that corresponds to that header. The following is how I picture it working:

for(i in 1:max(month)){
### `r month.name[i]` Air quaility

```{r, echo=FALSE}
plot(airquality[airquality$Month == 5,])
```
}

This ofcourse just prints the for loop as text, if i surround the for loop with r`` I would just get an error.

I want the code to produce an rmd file that looks like this:

May Air Quality

Plot

June Air Quality

plot

and so on and so forth. any ideas? I cannot use latex because I at my work they do not let us download exe files, and I do not know how to use latex anyways. I want to produce a word document.

回答1:

You can embed the markdown inside the loop using cat().

Note: you will need to set results="asis" for the text to be rendered as markdown. Note well: you will need two spaces in front of the \n new line character to get knitr to properly render the markdown in the presence of a plot out.

# Monthly Air Quality Graphs
```{r pressure,fig.width=6,echo=FALSE,message=FALSE,results="asis"}

attach(airquality)
for(i in unique(Month)) {
  cat("  \n###",  month.name[i], "Air Quaility  \n")
  #print(plot(airquality[airquality$Month == i,]))
  plot(airquality[airquality$Month == i,])
  cat("  \n")
}
```

来源：https://stackoverflow.com/questions/36373630/how-to-create-a-loop-that-includes-both-a-code-chunk-and-text-with-knitr-in-r

标签

loops

knitr