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

Question

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.

Answer 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") } ```