How can I draw a flow chart in ggplot2?

I want to draw this kind of flow chart in R using ggplot2 package.

I tried using ggflowchart package. My code is as follows:

library(tidyverse)
library(ggflowchart)
library(rcartocolor)
workflow <- tibble::tibble(from = c("RMD","MD","MD","MD","LaTeX"), to = c("MD","LaTeX","HTML","WORD","PDF"))
ggflowchart(workflow)
node_data <- tibble::tibble(name = c("RMD","MD","LaTeX","HTML","WORD","PDF"), label = c("RMD","MD","LaTeX","HTML","WORD","PDF"))
ggflowchart(workflow,node_data)                          
quarto <- ggflowchart(workflow,
            node_data,
            colour = "#585c45",
            text_colour = "#585c45",
            arrow_colour = "#585c45"
)+
  scale_fill_carto_d(palette = "Antique") +
  labs(title = "R Markdown Workflow") +
  theme(
    legend.position = "none",
    plot.background = element_rect(
      colour = "#f2e4c1",
      fill = "#f2e4c1"
    ),
    plot.title = element_text(
      size = 20,
      hjust = 0.5,
      face = "bold",
      colour = "#585c45"
    )
  )

I want the diagram to flow from left to right (i.e., the "RMD" node on left, and "PDF" on right). But in this code, it flows from up to down. I also want the writings along side the arrows, as shown in the link above. How can I do this?

I have no experience with ggflowchart(). Here is an alternative suggestion udinh DiagrammR:

library(DiagrammeR)

flow_chart <- grViz("digraph {
  
  # horizontal alignment
  graph [rankdir = LR]
  
  # Nodes with labels
  node [shape = box]
  RMD [label = 'RMD']
  MD [label = 'MD']
  LaTeX [label = 'LaTeX']
  HTML [label = 'HTML']
  WORD [label = 'WORD']
  PDF [label = 'PDF']
  
  # Edges with labels
  RMD -> MD [label = 'knit']
  MD -> LaTeX [label = 'pandoc']
  MD -> HTML [label = 'pandoc']
  MD -> WORD [label = 'pandoc']
  LaTeX -> PDF [label = 'pdflatex']
}")

flow_chart

At this stage I don't think it's possible to add text next to the arrows within the ggflowchart package, maybe DiagrammeR is an alternative option for that.

To enable horizontal flow, just use horizontal = TRUE. Use annotate to place custom labels onto the ggplot (note the "labels" on the first arrow in my example), but that would be very manual.

library(ggflowchart)
library(rcartocolor)
library(tidyverse)

workflow <- tibble::tibble(from = c("RMD","MD","MD","MD","LaTeX"), to = c("MD","LaTeX","HTML","WORD","PDF"))
node_data <- tibble::tibble(name = c("RMD","MD","LaTeX","HTML","WORD","PDF"), label = c("RMD","MD","LaTeX","HTML","WORD","PDF"))
               
quarto <- ggflowchart(workflow,
                      node_data,
                      colour = "#585c45",
                      text_colour = "#585c45",
                      arrow_colour = "#585c45",
                      horizontal = T
)+
  scale_fill_carto_d(palette = "Antique") +
  labs(title = "R Markdown Workflow") +
  theme(
    legend.position = "none",
    plot.background = element_rect(
      colour = "#f2e4c1",
      fill = "#f2e4c1"
    ),
    plot.title = element_text(
      size = 20,
      hjust = 0.5,
      face = "bold",
      colour = "#585c45"
    )
  ) +
  annotate(geom = "text", x = 0.1, y = 2.5, label = "labels")
quarto

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^{Created on 2023-05-14 with reprex v2.0.2}

With the current dev version of {ggflowchart} (version >= 1.0.0.9006), it's possible to directly add arrow labels. Install dev version

remotes::install_github("nrennie/ggflowchart")

You can add arrow labels by adding a label column to the data argument. The colour of the labels can be edited using arrow_label_fill:

library(tidyverse)
library(ggflowchart)
library(rcartocolor)
workflow <- tibble::tibble(from = c("RMD","MD","MD","MD","LaTeX"),
                           to = c("MD","LaTeX","HTML","WORD","PDF"),
                           label = c("knitr", NA, NA, NA, NA))
node_data <- tibble::tibble(name = c("RMD","MD","LaTeX","HTML","WORD","PDF"),
                            label = c("RMD","MD","LaTeX","HTML","WORD","PDF"))

ggflowchart(workflow,node_data, horizontal = TRUE, arrow_label_fill = "#f2e4c1") +
  scale_fill_carto_d(palette = "Antique") +
  labs(title = "R Markdown Workflow") +
  theme(
    legend.position = "none",
    plot.background = element_rect(
      colour = "#f2e4c1",
      fill = "#f2e4c1"
    ),
    plot.title = element_text(
      size = 20,
      hjust = 0.5,
      face = "bold",
      colour = "#585c45"
    )
  )