2021-08-04-log-plot.Rmd

---
description: How to make Log Plots in ggplot2 with Plotly.
name: Log Plots
permalink: ggplot2/log-plot/
thumnail_github: log-plot.png
layout: base
language: ggplot2
display_as: scientific
page_type: u-guide
order: 5
output:
  html_document:
    keep_md: true
---

```{r, echo = FALSE, message=FALSE}
knitr::opts_chunk$set(message = FALSE, warning=FALSE)
```

## Setting axis to log2 scale


```{r}
library(plotly)
library(ggplot2)

ToothGrowth$dose <- as.factor(ToothGrowth$dose)

p <- ggplot(cars, aes(x = speed, y = dist)) +
  geom_point()

p <- p + scale_x_continuous(trans = 'log2') +
  scale_y_continuous(trans = 'log2')

ggplotly(p)
```


You can also format the axis ticks to be displayed as exponents.


```{r}
library(plotly)
library(ggplot2)
library(scales)

ToothGrowth$dose <- as.factor(ToothGrowth$dose)

p <- ggplot(cars, aes(x = speed, y = dist)) +
  geom_point()

p <- p + scale_x_continuous(trans = 'log2') +
  scale_y_continuous(trans = 'log2')

p <- p + scale_y_continuous(trans = log2_trans(),
    breaks = trans_breaks("log2", function(x) 2^x),
    labels = trans_format("log2", math_format(2^.x)))


ggplotly(p)
```

<!--------------------- EXAMPLE BREAK ------------------------->

## Setting axis to log10 scale


```{r}
library(plotly)
library(ggplot2)

ToothGrowth$dose <- as.factor(ToothGrowth$dose)

p <- ggplot(cars, aes(x = speed, y = dist)) +
  geom_point()

p <- p + scale_y_log10()


ggplotly(p)
```
ternatively, you can use the function `scale_y_continuous(trans = "log10")`, which allows to transform breaks and the format of labels.

<!--------------------- EXAMPLE BREAK ------------------------->