Add hover text or text annotation in plotly gauge chart - r

Question

Can we add hovertext or text annotation in a plotly gauge chart? For example in my plot below I want to add in the green area hover or text or both "Uptake first dose%: 19.8" and in the gray area "Not vaccinated (%):80.2"
library(plotly)
fig <- plot_ly(
type = "indicator",
mode = "gauge+number+delta",
value = 19.8,
title = list(text = "Uptake first dose %", font = list(size = 24)),
delta = list(reference = 70, increasing = list(color = "gray")),
gauge = list(
axis = list(range = list(NULL, 100), tickwidth = 1, tickcolor = "lightgreen"),
bar = list(color = "lightgreen"),
bgcolor = "white",
borderwidth = 2,
bordercolor = "gray",
steps = list(
list(range = c(0, 50), color = "lightgreen"),
list(range = c(20, 100), color = "gray")),
threshold = list(
line = list(color = "black", width = 4),
thickness = 0.75,
value = 70)))
fig <- fig %>%
layout(
margin = list(l=20,r=30),
paper_bgcolor = "lavender",
font = list(color = "darkblue", family = "Arial"))
fig

Answer 1

You can add annotations but I couldn't find a way to get the hovertext without an annotation.
fig <- plotly::plot_ly(
type = "indicator",
mode = "gauge+number+delta",
value = 19.8,
title = list(text = "Uptake first dose %", font = list(size = 24)),
delta = list(reference = 70, increasing = list(color = "gray")),
gauge = list(
axis = list(range = list(NULL, 100), tickwidth = 1, tickcolor = "lightgreen"),
bar = list(color = "lightgreen"),
bgcolor = "white",
borderwidth = 2,
bordercolor = "gray",
steps = list(
list(range = c(0, 50), color = "lightgreen"),
list(range = c(20, 100), color = "gray")),
threshold = list(
line = list(color = "black", width = 4),
thickness = 0.75,
value = 70)))
fig <- fig %>%
plotly::layout(
margin = list(l=20,r=30),
paper_bgcolor = "lavender",
font = list(color = "darkblue", family = "Arial"),
annotations = list(x = 0.05, y = 0.3, text = "19.8%",
hovertext = "Your Text",
showarrow = FALSE))
fig
You could also use add_annotations if you want to add multiples.
See https://plotly.com/r/text-and-annotations/