Plotly R order scatter plot legend entries - r

Question

I create a plot in the following manner:
## generate test data
getTestData <- function(seed_val=711, noise=1.0) {
set.seed(seed_val)
d <- seq(as.Date('2017/01/01'), as.Date('2017/01/08'), "days")
first_name <- rep("Jane", 8)
first_name <- append(first_name, rep("Fred", 8))
first_name <- append(first_name, rep("Sally", 8))
y1_vals <- seq(1, 3*8, 1)
y2_vals <- rnorm(3*8, mean=y1_vals, sd=noise)
dat <- data.frame(date=d, f_name=first_name, y1=y1_vals, y2=y2_vals,
stringsAsFactors = FALSE)
return(dat)
}
dat <- getTestData()
library(dplyr)
library(plotly)
p1 <- plot_ly(dat, x=~date, y=~y1, color=~f_name,
type = 'scatter', mode = "lines+markers") %>%
layout(yaxis = list(title = "some important y value")) %>%
add_trace(y=~y2, name='actual', showlegend=FALSE,
type='scatter', mode='lines',
line=list(width = 2, dash = 'dash'), color=~f_name)
Plotly orders the legend alphabetically by the f_name grouping, but I want this order to be: Jane, Fred, Sally which is the original order in the data frame
The accepted answer given here:
Plotly R order legend entries
in the section commented as #Set sort argument to FALSE and now orders like the data frame is very close to what I need, but this solution is for a pie chart. I need to reorder my legend in a scatterplot which doesn't appear to have a sort parameter available to set (like the pie chart does).

Answer 1

Is this what you want?
dat$f_name <- factor(dat$f_name, levels = c("Jane", "Fred", "Sally"))
plot_ly(dat, x=~date, y=~y1, color=~f_name,
type = 'scatter', mode = "lines+markers") %>%
layout(yaxis = list(title = "some important y value")) %>%
add_trace(y=~y2, name='actual', showlegend=FALSE,
type='scatter', mode='lines',
line=list(width = 2, dash = 'dash'), color=~f_name)

Answer 2

To add something to previous answer, you can also choose colors for names. Note I added Peter to show that if whenever it appears Peter (not this case), its color would be gray (I needed to choose colors in shiny and I needed them to be the same, whether they appeared or not, or in casi they appear)
dat$f_name <- factor(dat$f_name, levels = c("Jane", "Fred", "Sally", "Peter"))
ccolors <- c('black', 'blue','red', 'gray')
plot_ly(dat, x=~date, y=~y1, color=~f_name, colors=ccolors,
type = 'scatter', mode = "lines+markers") %>%
layout(yaxis = list(title = "some important y value")) %>%
add_trace(y=~y2, name='actual', showlegend=FALSE,
type='scatter', mode='lines',
line=list(width = 2, dash = 'dash'), color=~f_name)