Adding 'name' parameter to plot_ly() function removes factor ordering.

We sometimes use the 'name' parameter within the plot_ly() function to add a suffix to the values shown in a legend. Values in the legend are shown because a variable (legend variable) is used for the 'color' parameter in plot_ly().

Since a few days/weeks, using this method to add a suffix leads to the ordering of 'legend variable' to switch to alphabetical order instead of its original factor levels.

I added an example below.

library(plotly)
library(lubridate)

factor <- factor(x = c('bbb', 'ccc', 'aaa'), levels = c('bbb', 'ccc', 'aaa'))
number <- c(1,2,3)
date <- c(ymd(20170101), ymd(20170202), ymd(20170303))

levels(factor)

df <- data.frame(letter = factor, number = number, date = date)

levels(df$letter)

plot_ly(df, x = ~number, y = ~date, type = 'bar', color = ~letter)
plot_ly(df, x = ~number, y = ~date, type = 'bar', color = ~letter, name = 'ff')
plot_ly(df, x = ~number, y = ~date, type = 'bar', color = ~letter, name = c('asd', 'ff', 'ss'))

まず、color = ~letter を指定した plot_ly() の再現可能な R の例を実行します。最初は name なしで実行し、その後、name の各形式で実行します。plot_ly() による因子レベルと凡例名の処理を追跡します。完了条件は、示されているすべてのケースで凡例が因子の順序 bbb, ccc, aaa を保持することです。