Not able to show Regression Line Equation using ggplotly

[romabhu]

I need to display Regression Line Equation with the lineplot. I am using "stat_poly_eq" function present in "ggpmisc" package. Able to achieve it with ggplot (Find attached screenshot). But when when I am trying to show plot using ggplotly regression equition is getting disppeared (Find attached screenshot)

Below is the sample code, I am using:

library(ggplot2)
library(ggpmisc)
library(plotly)
df <- data.frame(x = c(1:100))
df$y <- 2 + 3 * df$x + rnorm(100, sd = 40)
my.formula <- y ~ x
p <- ggplot(data = df, aes(x = x, y = y)) +
geom_smooth(method = "lm", se=FALSE, color="black", formula = my.formula) +
stat_poly_eq(formula = my.formula,
aes(label = paste(..eq.label.., ..rr.label.., sep = "~~~")),
parse = TRUE) +
geom_point()
print(p)
ggplotly(p)

Please suggest probable solution with which i can achieve this. It is really urgent for me to show quation using ggplotly.

[cpsievert]

Added to #566

[aphalo]

Layer function stat_poly_equation() is flexible enough to work with 'ggplotly' if some defaults are overriden. One needs to be careful about the positioning of the text labels as some manual tweaking is required.

library(ggplot2)
library(ggpmisc)
library(plotly)

df <- data.frame(x = c(1:100))
df$y <- 2 + 3 * df$x + rnorm(100, sd = 40)

The geom used by default is geom_text_npc() from 'ggpp', which is unknown to 'ggplotly', so we need to use geom_text() instead. 'ggplotly' does not seem to understand character strings that are meant to be parsed into expressions or even respect justification in geom_text(). However, there are workarounds available for all these limitations. The pure-text labels lack italics and super- and subscripts, as stat_poly_eq() currently uses the ASCII character set for equations formatted with output.type = "text".

my.formula <- y ~ x
p <-
  ggplot(data = df, aes(x = x, y = y)) +
  geom_smooth(method = "lm", se=FALSE, color="black", formula = my.formula) +
  stat_poly_eq(geom = "text", # override default "text_npc"
                       output.type = "text",  # override default "expression"
                       formula = my.formula,
                       aes(label = paste(..eq.label.., ..rr.label.., sep = ",  ")), # use for sep plain text
                       label.x = 20) + # override default "left"
  geom_point()

ggplotly(p)

This PNG is downloaded from the plotly plot.

[aphalo]

@cpsievert I think the best way to enhance 'ggplotly' would be to implement support for geom_richtext() from package 'ggtext'.