How to add a greek letter to an axis label to a 3D plot in plotly?

December 15, 2024

I have below plot using plotly

library(plotly)
set.seed(1)
n <- 100
theta <- runif(n, 0, 2*pi)
u <- runif(n, -1, 1)


base<-'B1'
compare<-'A1'

p <- plot_ly(x = ~sqrt(1 - u^2) * cos(theta), y = ~sqrt(1 - u^2) * sin(theta), z = ~u) %>%
  layout(
    title = "Some plot",
    scene = list(
      yaxis = list(title = expression('theta'))
    ))
p

I wanted to add greek expression theta in the y-axis title, and tried using expression(theta), however it is not rendering.

Could you please find how is it possible to add greek letters in plotly?

>Solution :

One option would be to use UTF-8 codes, e.g. "\u03B8" for a theta

library(plotly)
set.seed(1)

n <- 100
theta <- runif(n, 0, 2*pi)
u <- runif(n, -1, 1)

base<-'B1'
compare<-'A1'

p <- plot_ly(x = ~sqrt(1 - u^2) * cos(theta), y = ~sqrt(1 - u^2) * sin(theta), z = ~u) %>%
  layout(
    title = "Some plot",
    scene = list(
      xaxis = list(title = list(text = "\u03B8")),
      yaxis = list(title = "Y-axis")
    ))
p