R Markdown - format text as a header in a loop seems to be working for 1st loop iteration only

Question

I am trying to generate R Markdown document with headers generated dynamically from a loop.

I used suggestions from similar SO questions: Knitr: print text from code block as R markdown, Using bold text in a loop for a Word document in Rmarkdown and wrote

---
title: "Untitled"
output:
  html_document:
    toc: true
    toc_depth: 5
---

## R Markdown

```{r, warning=FALSE, message=FALSE,  echo=FALSE}
library(ggplot2)
library(dplyr)
```

```{r fig.width=4, fig.height=2,  echo=FALSE, results='asis'}
experiment_names <- paste0("Experiment ", 1:3)

for (id in 1:3){ 

  cat("  \n")
  cat("### ",  experiment_names[id])
  cat("  \n")

  set.seed(id)
  plt <- 
    data.frame(x = rnorm(100)) %>%
    ggplot(aes(x = x)) + 
    geom_histogram(binwidth = 0.1)
  plot(plt)
}
```

but only the 1st loop iteration header is printed correctly. How to get the two others working too?

Nova Nova · Accepted Answer · 2020-04-20T19:07:53

I don't know why this works, but try one line instead of three:

cat("\n\n### ", experiment_names[id], "\n")

R Markdown - format text as a header in a loop seems to be working for 1st loop iteration only

1 Answers