determine the stack order in a stacked bar plot with r and plotly

Question

below is a simple example for stacked bar plot with r and plotly. By default, the stacks are alphabetly ordered. How can I determine other order?

library(plotly) 
bars <- c("bar1", "bar1", "bar2", "bar2")
category <- c("(order1)small value", "(order2)big value", "(order1)small value", "(order2)big value")
#category <- c("(order2)small value", "(order1)big value", "(order2)small value", "(order1)big value")
count <- c(3, 6, 2, 7)
data <- data.frame(bars, category, count)
#View(data)
p <- plot_ly(data,  x = ~bars, y = ~count, color = ~category) %>% 
layout(width = 460, height = 230, barmode = 'stack' ) 
p

E.g. I would like to be able to determine, that the category: "(order1)small value" to be on the top. Now it is on the bottom, because alphabetly it is before the other category.

Thank you very much in advance

Answer 1

Add this line before creating you data. With category as a factor you can controle the order of each level.

category  <-  factor(category, c("(order2)big value", "(order1)small value"))