Cómo representar una curva logarítmica en R

Problema

Queremos ajustar una curva logarítmica a un diagrama de dispersión.

library(ggplot2)
ggplot(mpg, aes(displ, hwy)) +
  geom_point()

Solución

Paquete base

plot(hwy ~ displ, mpg)
logEstimate <- lm(hwy ~ log(displ), data = mpg)
curve(coef(logEstimate)[1] + coef(logEstimate)[2] * log(x), add = TRUE)

ggplot2

ggplot(mpg, aes(displ, hwy)) +
  geom_point() +
  stat_smooth(method = "lm", formula = y ~ log(x))

Referencias

• stackoverflow

How to plot a log curve in R

Problem

We want to fit a logarithmic curve to a scatterplot.

library(ggplot2)
ggplot(mpg, aes(displ, hwy)) +
  geom_point()

Solution

Base package

plot(hwy ~ displ, mpg)
logEstimate <- lm(hwy ~ log(displ), data = mpg)
curve(coef(logEstimate)[1] + coef(logEstimate)[2] * log(x), add = TRUE)

ggplot2

ggplot(mpg, aes(displ, hwy)) +
  geom_point() +
  stat_smooth(method = "lm", formula = y ~ log(x))

References

• stackoverflow

Cómo controlar la dispersión de puntos dentro de un diagrama de violín con ggplot2

Problem

Queremos controlar la dispersión de puntos dentro de un diagrama de violín con ggplot2.

library(tidyverse)
p <- ggplot(mpg, aes(class, hwy))
p + geom_violin() + geom_jitter()

Solución

• Opción 1
Ampliamos la anchura del diagrama de violín (width = 1.3), y jugamos con la transparencia y la variación horizontal de geom_ jitter con (width = .02). No es una opción enteramente satisfactoria. Al restringir la variación horizontal de geom_ jitter, limitamos la propia finalidad de la función que es evitar la superposición de puntos.

p + geom_violin(width = 1.3) + geom_jitter(alpha = 0.2, width = .02)


• Opción 2
Empleamos la función geom_quasirandom del paquete geom_beeswarm:

The quasirandom geom is a convenient means to offset points within categories to reduce overplotting. Uses the vipor package

library(ggbeeswarm)
p + geom_violin(width = 1.3) + geom_quasirandom(alpha = 0.2, width = 0.2)

Entradas relacionadas

• Versión en inglés: How to restrain scattered jitter points within a violin plot using ggplot2
• English posts

Referencias

• ggbeeswarm
• stackoverflow

How to restrain scattered jitter points within a violin plot using ggplot2

Problem

We would like to restrain the scattered jitter points within a violin plot using ggplot2.

library(tidyverse)
p <- ggplot(mpg, aes(class, hwy))
p + geom_violin() + geom_jitter()

Solution

• Option 1
Not a completely satisfactory option, because by restricting the horizontal jitter we defeat the purpose of handling overplotting. But we can enlarge the width of the violin plots (width = 1.3), and play with alpha for transparency and limit the horizontal jitter (width = .02).

p + geom_violin(width = 1.3) + geom_jitter(alpha = 0.2, width = .02)


• Option 2
Using the function geom_quasirandom from package geom_beeswarm:

The quasirandom geom is a convenient means to offset points within categories to reduce overplotting. Uses the vipor package

library(ggbeeswarm)
p + geom_violin(width = 1.3) + geom_quasirandom(alpha = 0.2, width = 0.2)

Related posts

• Spanish version: Cómo controlar la dispersión de puntos dentro de un diagrama de violín con ggplot2
• English posts

References

• ggbeeswarm
• stackoverflow