using a for loop to generate a series of plots in new powerpoint slides using quarto

Question

I am creating a quarto powerpoint presentation and want to use a dataset to iterate over all the classes in a variable and do a plot for each class on a new slide. However, my plot doesn't seem to show up

---
title: "test_quarto_presentation"
format: pptx
editor: visual
---

## Quarto

Trying to iterate over each species and print the distributions on slides

```{r}
library(tidyverse)
```

```{r, results='asis'}
for (species in unique(iris$Species)){
  cat(paste0('## ', species))
  print("test")
  
  print(iris %>%
           filter(Species == "virginica") %>%
           ggplot(aes(x = Petal.Length)) +
           geom_histogram())}
```

Answer 1

Here is an option by producing the plots beforehand using purrr based on this discussion:

---
title: "test_quarto_presentation"
format: pptx
---

```{r, include=FALSE}
library(tidyverse)
spec_name <- unique(iris$Species)

make_hist <- function(spec) {
 iris |> 
           filter(Species == spec) |> 
           ggplot(aes(x = Petal.Length)) +
           geom_histogram()
}
list_hist <- map(spec_name, make_hist)

df <- tibble(spec = spec_name, plots = list_hist)
```



```{r}
#| output: asis
res <- pmap_chr(df, \(spec, plots) {
  knitr::knit_child(text = c(
    "## `r spec`",
    "```{r}",
    "#| echo: false",
    "plots",
    "```",
    ""), envir = environment(), quiet = TRUE)
})
cat(res, sep = '\n')
```

Output: