R Plotly scatter ternary colorbar - r

Question

I am using Plotly to make a scatter ternary plot. I want to color points by one of the values in the data frame (titled mu). However, the colorbar isn't showing. Here is my code:
library(plotly)
df <- eqData0
# axis layout
axis <- function(title) {
list(
title = title,
titlefont = list(
size = 20
),
tickfont = list(
size = 15
),
tickcolor = 'rgba(0,0,0,0)',
ticklen = 5
)
}
fig <- df %>% plot_ly()
fig <- fig %>% add_trace(
type = 'scatterternary',
mode = 'markers',
a = ~u1eq,
b = ~u2eq,
c = ~bueq,
marker = list(
symbol = 100,
color = ~mu,
size = 14,
line = list('width' = 2),
colorscale = 'YlGnBu'
),
colorbar = list(
xanchor = 'middle',
yanchor = 'middle'
)
)
m <- list(
l = 50,
r = 50,
b = 100,
t = 100,
pad = 4
)
fig <- fig %>% layout(autosize = F, width = 500, height = 500, margin = m,
ternary = list(
sum = 1,
aaxis = axis(TeX("$u_1$")),
baxis = axis(TeX("$u_2$")),
caxis = axis(TeX("$\\bar{u}$"))
)
)
fig <- fig %>% config(mathjax = 'cdn')
fig
Somehow the colorbar is still not showing! I'm not sure why because all the Plotly scatterplot examples online make getting the colorbar to show up seem easy.

Answer 1

It looks like you were missing showscale=TRUE in the trace definition.
Trying:
#fake data:
df <- data.frame(u1eq = c(0.2, 0.3, 0.5), u2eq=c(0.6, 0.3, 0.1), bueq=c(0.2, 0.4, 0.4), mu=c(1, 1.8, 2))
# axis layout
axis <- function(title) {
list(
title = title,
titlefont = list(
size = 20
),
tickfont = list(
size = 15
),
tickcolor = 'rgba(0,0,0,0)',
ticklen = 5
)
}
fig <- df %>% plot_ly()
fig <- fig %>% add_trace(
type = 'scatterternary',
mode = 'markers',
a = ~u1eq,
b = ~u2eq,
c = ~bueq,
marker = list(
colorscale = 'YlGnBu',
symbol = 100,
color = ~mu,
size = 14,
line = list('width' = 2),
showscale = TRUE
)
)
m <- list( l = 50, r = 50, b = 100, t = 100, pad = 4)
fig <- fig %>% layout(autosize = F, width = 500, height = 500, margin = m,
ternary = list(
sum = 1,
aaxis = axis(TeX("$u_1$")),
baxis = axis(TeX("$u_2$")),
caxis = axis(TeX("$\\bar{u}$")) )
) %>% config(mathjax = 'cdn')
fig