Rlot中的Plot.ly：x轴的不需要的字母排序

Question

I tried for hours, but I could not succeed. My data frame is simply

df <- as.data.frame(matrix(c("g","d","a","b","z",5,4,3,2,1),5,2))

library("plotly")
p <- plot_ly(data = df,x = ~V1,y = ~V2,type = "scatter",mode = "lines+markers") %>%
layout(title = "my title")
p

So, this give me

But I don't want x axis to be sorted alphabetically, I just want to keep the order as it is and see a decreasing graph.

Answer 1

First of all, a matrix can only hold data of one class. Hence you have a matrix of strings that you are converting to a data.frame . Because by default stringAsFactors = TRUE , your character matrix is converted to a data.frame of factor 's, where the levels of your two columns are by default sorted. Alphabetically for V1 and in increasing order for V2 .

If you don't wish to modify the data directly to remedy the issue at the source - as pointed out in the other answers, you can altenatively use plotly 's categoryorder = argument inside layout() in the following way:

library(plotly)
xform <- list(categoryorder = "array",
              categoryarray = df$V1)

plot_ly(data = df,
        x = ~V1,
        y = ~V2,
        type = "scatter",
        mode = "lines+markers") %>%
        layout(title = "my title",
               xaxis = xform)

Answer 2

> df <- as.data.frame(matrix(c("g","d","a","b","z",5,4,3,2,1),5,2))
> str(df)
'data.frame':   5 obs. of  2 variables:
$ V1: Factor w/ 5 levels "a","b","d","g",..: 4 3 1 2 5
$ V2: Factor w/ 5 levels "1","2","3","4",..: 5 4 3 2 1
> df$V1
[1] g d a b z
Levels: a b d g z
> df$V1 <- ordered(df$V1, c("g","d","a","b","z"))
> df$V1
[1] g d a b z
Levels: g < d < a < b < z