R markdown: Reduce the space between two plots in pdf output document

Question

• Aim: R markdown: To construct one DinA4 pdf page with a rectangle on the top left side and two plots.
• Problem: After drawing the rectangle, the next plot is far away with a large white space in between.
• Desired Output: Heatmap should appear immediately after the rectangle may with one or two white lines.

I guess the problem is the drawing of the rectangle. Here I need some help. Thank you.

---
output:
  pdf_document
documentclass: article
classoption: a4paper
geometry: margin=1cm

subparagraph: yes
header-includes: |
  \usepackage{titlesec}
  \titlespacing{\title}{0pt}{\parskip}{-\parskip}

title: "Example of Title to Body Text"
subtitle: Subtitle Places Here
---

\vspace{-5truemm}
\pagenumbering{gobble}

#``` {r setup, include=FALSE}
knitr::opts_chunk$set(echo = FALSE)
library(draw)
library(ggplot2)
library(dplyr)
# ```

#```{r rectangle}
drawBox(x =2, y = 3.5, width = 2.5, height = 1)
#```

#```{r heatmap}
df <- data.frame(
  test_id = c(1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
              3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4),
  test_nr = c(1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 
              1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 1, 1, 1, 1, 2, 2, 2, 2),
  region = c("A", "B", "C", "D", "A", "B", "C", "D", "A", "B", "C", "D", "A", 
             "B", "C", "D", "A", "B", "C", "D", "A", "B", "C", "D", "A", "B", 
             "C", "D", "A", "B", "C", "D", "A", "B", "C", "D", "A", "B", "C", "D"),
  test_value = c(3, 1, 2, 2, 2, 1, 2, 2, 3, 2, 2, 3, 2, 1, 2, 2, 1, 2, 3, 
                 4, 2, 1, 1, 2, 1, 1, 1, 1, 2, 2, 3, 2, 2, 2, 99, 99, 3, 3, 3, 3)
)

# named vector for heatmap
cols <-  c("1" = "green", 
           "2" = "darkgreen", 
           "3" = "orange", 
           "4" = "red",
           "99" = "black")
labels_legend <- c("1" = "very good", 
                   "2" = "good", 
                   "3" = "not so good", 
                   "4" = "bad", 
                   "99" = "NA")

df <- df %>% 
  filter(test_id==1)

ggplot(
  df, 
  aes(region, test_nr)) +
  geom_tile(aes(fill= factor (test_value))) +
  geom_text(aes(label = test_value), size = 10, color = "white") + # text in tiles
  scale_colour_manual(
    values = cols, 
    breaks = c("1", "2", "3", "4", "99"),
    labels = labels_legend,
    aesthetics = c("colour", "fill")
  ) +
  theme(text = element_text(size = 14)) + # this will change all text size
  labs(title =  "Test (Individual heatmap)", x = "Region", y = "Event") +
  labs(fill = "Test") +
  coord_fixed(ratio=1, clip="on") +
  theme(axis.text.y = element_text(face = "bold", size = 12)) +
  theme(axis.text.x = element_text(angle = 0, face = "bold", size = 12)) +
  theme(axis.line = element_line(colour = "darkblue", 
                                 size = 1, linetype = "solid")
  )
# ```

## Information

Answer 1

You can use the subfigure environment to display multiple plots side by side, though you may not want to place the rectangle under the same main caption as the heatmap.

---
output:
  pdf_document:
    extra_dependencies: "subfig"
documentclass: article
classoption: a4paper
geometry: margin=1cm

subparagraph: yes
header-includes: |
  \usepackage{titlesec}
  \titlespacing{\title}{0pt}{\parskip}{-\parskip}

title: "Example of Title to Body Text"
subtitle: Subtitle Places Here
---

\vspace{-5truemm}
\pagenumbering{gobble}

``` {r setup, include=FALSE}
knitr::opts_chunk$set(echo = FALSE)
library(draw)
library(ggplot2)
library(dplyr)
```

```{r rectangle}
drawBox(x =2, y = 3.5, width = 2.5, height = 1)
```

```{r heatmap-data}
df <- data.frame(
  test_id = c(1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
              3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4),
  test_nr = c(1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 
              1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 1, 1, 1, 1, 2, 2, 2, 2),
  region = c("A", "B", "C", "D", "A", "B", "C", "D", "A", "B", "C", "D", "A", 
             "B", "C", "D", "A", "B", "C", "D", "A", "B", "C", "D", "A", "B", 
             "C", "D", "A", "B", "C", "D", "A", "B", "C", "D", "A", "B", "C", "D"),
  test_value = c(3, 1, 2, 2, 2, 1, 2, 2, 3, 2, 2, 3, 2, 1, 2, 2, 1, 2, 3, 
                 4, 2, 1, 1, 2, 1, 1, 1, 1, 2, 2, 3, 2, 2, 2, 99, 99, 3, 3, 3, 3)
)

# named vector for heatmap
cols <-  c("1" = "green", 
           "2" = "darkgreen", 
           "3" = "orange", 
           "4" = "red",
           "99" = "black")
labels_legend <- c("1" = "very good", 
                   "2" = "good", 
                   "3" = "not so good", 
                   "4" = "bad", 
                   "99" = "NA")

df <- df %>% 
  filter(test_id==1)
```

```{r heatmap, fig.show="hold", fig.cap='Rectangle and Heatmap', fig.subcap=c('LEFT', 'RIGHT'), out.width='50%', fig.align = "center"}
drawBox(x =2, y = 3.5, width = 2.5, height = 1)

ggplot(
  df, 
  aes(region, test_nr)
  ) +
  geom_tile(aes(fill= factor (test_value))) +
  geom_text(aes(label = test_value), size = 10, color = "white") + # text in tiles
  scale_colour_manual(
    values = cols, 
    breaks = c("1", "2", "3", "4", "99"),
    labels = labels_legend,
    aesthetics = c("colour", "fill")
  ) +
  theme(text = element_text(size = 14)) + # this will change all text size
  labs(title =  "Test (Individual heatmap)", x = "Region", y = "Event") +
  labs(fill = "Test") +
  coord_fixed(ratio=1, clip="on") +
  theme(axis.text.y = element_text(face = "bold", size = 12)) +
  theme(axis.text.x = element_text(angle = 0, face = "bold", size = 12)) +
  theme(
    axis.line = element_line(
      colour = "darkblue", 
      size = 1, linetype = "solid"
      )
  )
```

## Information