How to change the spacing between the legend and the panel in ggplot2

Problema

We want to increase the spacing between the legend and the panel in ggplot2.

library(ggplot2)
xy <- data.frame(x = 1:10, y = 10:1, type = rep(LETTERS[1:2], each=5))
plot <- ggplot(data = xy) +
        geom_point(aes(x = x, y = y, colo r= type))

Solution

We use the argument legend.box.margin to add 20 points to the left.

plot <- plot + theme(legend.box.margin = margin(0, 0, 0, 20))

References

• stackoverflow

How to add a text box to a plot in R

Problem

We want to add a text box to a plot in R. First, we will use a very convoluted code to get it done.

# A plot
plot(x = runif(1000), y = runif(1000), type = "p", pch = 16, col = "#40404050")

# Text box parameters
myText <- "some Text"
posCoordsVec <- c(0.5, 0.5)
cex <- 2

# Rectangle
textHeight <- graphics::strheight(myText, cex = cex)
textWidth <- graphics::strwidth(myText, cex = cex)
pad <- textHeight*0.3
rect(xleft = posCoordsVec[1] - textWidth/2 - pad, 
        ybottom = posCoordsVec[2] - textHeight/2 - pad, 
        xright = posCoordsVec[1] + textWidth/2 + pad, 
        ytop = posCoordsVec[2] + textHeight/2 + pad,
        col = "lightblue", border = NA)

# Text coordinates
text(posCoordsVec[1], posCoordsVec[2], myText, cex = cex)

Solution

• Base graphics

We use the function legend, same colour for the box line (box.col) and the background (bg), adjusting the text inside with the argument adj.

plot(x = runif(1000), y = runif(1000), type = "p", pch = 16, col = "#40404050")
legend(0.4, 0.5, "Some text", box.col = "lightblue", bg = "lightblue", adj = 0.2)


• ggpplot2

With ggplot2 we need the function geom_label. The text will be automatically aligned inside the box, we remove the borders with label.size = NA.

library(ggplot2)
df <- data.frame(x = runif(1000), y = runif(1000))
ggplot(data = df, aes(x = x , y = y))+ 
  geom_point(alpha = 0.2)+
  geom_label(aes(x = 0.5, y = 0.5, label = "Some text"), 
             fill = "lightblue", label.size = NA, size = 5)

References

• stackoverflow
• legend
• geom_label

Spacing between legend keys in ggplot2

Problem

We want to add some spacing between the elements of the legend to the following plot using ggplot2.

library(tidyverse)
mtcars %>%
  mutate(transmission = ifelse(am, "manual", "automatic")) %>%
  ggplot() +
  aes(x = transmission, fill = transmission) +
  geom_bar() +
  labs(fill = NULL) +
  theme(
    #legend.spacing.x = unit(.5, "char"), # adds spacing to the left too
    legend.position = "top",
    legend.justification = c(0, 0),
    legend.title = element_blank(),
    legend.margin = margin(c(5, 5, 5, 0))
  )

Solution

First option: spacing between the 4 elements

We use legend.spacing.x to add the spacing between the 4 elements the legend's key and text.

mtcars %>%
  mutate(transmission = ifelse(am, "manual", "automatic")) %>%
  ggplot() +
  aes(x = transmission, fill = transmission) +
  geom_bar() +
  labs(fill = NULL) +
  theme(
    legend.spacing.x = unit(.5, "char"),
    legend.position = "top",
    legend.justification = c(0, 0),
    legend.title = element_blank(),
    legend.margin = margin(c(5, 5, 5, 0)))

Second option: spacing between the 2 groups automatic and manual

We pass the argument margin to he element_text function to add spacing only between the 2 groups, the two types of transmissions automatic and manual, between the text automatic and the key (blue square) of manual

mtcars %>%
  mutate(transmission = ifelse(am, "manual", "automatic")) %>%
  ggplot() +
  aes(x = transmission, fill = transmission) +
  geom_bar() +
  labs(fill = NULL) +
  theme(legend.position = "top",
    legend.justification = c(0, 0),
    legend.title = element_blank(),
    legend.margin = margin(c(5, 5, 5, 0)),
    legend.text = element_text(margin = margin(r = 10, unit = "pt")))

Related posts

• Spanish version

References

• stackoverflow
• Modify components of a theme

Ajustar espacio entre los elementos de una leyenda en ggplot2

Problema

Tenemos el siguiente gráfico en el que deseamos separar los dos elementos de la leyenda: automatic y manual.

library(tidyverse)
mtcars %>%
  mutate(transmission = ifelse(am, "manual", "automatic")) %>%
  ggplot() +
  aes(x = transmission, fill = transmission) +
  geom_bar() +
  labs(fill = NULL) +
  theme(
    #legend.spacing.x = unit(.5, "char"), # adds spacing to the left too
    legend.position = "top",
    legend.justification = c(0, 0),
    legend.title = element_blank(),
    legend.margin = margin(c(5, 5, 5, 0))
  )

Solución

Primera opción: espacio entre los 4 elementos

Empleamos legend.spacing.x que crea un espacio entre los 4 elementos, las muestras de color y los textos.

mtcars %>%
  mutate(transmission = ifelse(am, "manual", "automatic")) %>%
  ggplot() +
  aes(x = transmission, fill = transmission) +
  geom_bar() +
  labs(fill = NULL) +
  theme(
    legend.spacing.x = unit(.5, "char"),
    legend.position = "top",
    legend.justification = c(0, 0),
    legend.title = element_blank(),
    legend.margin = margin(c(5, 5, 5, 0)))

Segunda opción: espacio entre los 2 grupos de elementos

Empleamos margin dentro de element_text para crear un espacio solamente entre los grupos de elementos, el correspondiente a la serie automatic y el correspondiente a manual.

mtcars %>%
  mutate(transmission = ifelse(am, "manual", "automatic")) %>%
  ggplot() +
  aes(x = transmission, fill = transmission) +
  geom_bar() +
  labs(fill = NULL) +
  theme(legend.position = "top",
    legend.justification = c(0, 0),
    legend.title = element_blank(),
    legend.margin = margin(c(5, 5, 5, 0)),
    legend.text = element_text(margin = margin(r = 10, unit = "pt")))

Entradas relacionadas

• legend

Referencias

• stackoverflow
• Modify components of a theme

Añadir un cuadro de texto a un gráfico en R

Problema

Queremos añadir un cuadro de texto a un gráfico en R. A continuación, podemos ver una primera solución, pero el código es demasiado verboso y alambicado.

# Un gráfico
plot(x = runif(1000), y = runif(1000), type = "p", pch = 16, col = "#40404050")

## Parámetros para el texto
myText <- "some Text"
posCoordsVec <- c(0.5, 0.5)
cex <- 2

# Rectángulo
textHeight <- graphics::strheight(myText, cex = cex)
textWidth <- graphics::strwidth(myText, cex = cex)
pad <- textHeight*0.3
rect(xleft = posCoordsVec[1] - textWidth/2 - pad, 
        ybottom = posCoordsVec[2] - textHeight/2 - pad, 
        xright = posCoordsVec[1] + textWidth/2 + pad, 
        ytop = posCoordsVec[2] + textHeight/2 + pad,
        col = "lightblue", border = NA)

# Ubicación del texto
text(posCoordsVec[1], posCoordsVec[2], myText, cex = cex)

Solución

• Base graphics

Empleamos la función legend, con el mismo color en los bordes y relleno que en la solución inicial, y ajustamos el texto en el interior con el argumento adj.

plot(x = runif(1000), y = runif(1000), type = "p", pch = 16, col = "#40404050")
legend(0.4, 0.5, "Some text", box.col = "lightblue", bg = "lightblue", adj = 0.2)


• ggpplot2

Con ggplot2 usamos la función geom_label. A diferencia de legend en base graphcis, el texto se centra automáticamente dentro del cuadro, con label.size = NA eliminamos los bordes

library(ggplot2)
df <- data.frame(x = runif(1000), y = runif(1000))
ggplot(data = df, aes(x = x , y = y))+ 
  geom_point(alpha = 0.2)+
  geom_label(aes(x = 0.5, y = 0.5, label = "Some text"), 
             fill = "lightblue", label.size = NA, size = 5)

Referencias

• stackoverflow
• legend
• geom_label

Ajustar el espacio entre el gráfico y la leyenda en ggplot2

Problema

Queremos aumentar la distancia de separación entre el gráfico y la legenda usando el paquete ggplot2.

library(ggplot2)
xy <- data.frame(x = 1:10, y = 10:1, type = rep(LETTERS[1:2], each=5))
plot <- ggplot(data = xy) +
        geom_point(aes(x = x, y = y, colo r= type))

Solución

plot <- plot + theme(legend.box.margin = margin(0, 0, 0, 20))

Referencias

• stackoverflow