R Plotly dropdown variable selection with color

Question

This question is related to some others on SO but I haven't found a solution yet.

I'm looking to use plotly's dropdown functionality to select which variable gets plotted on the x-axis, similar to this question/answer that's been super helpful in getting me to where I am now.

I'm now trying to use the color argument in plot_ly to color the markers in my plot. However, when I use the dropdown to change the x-variable, it seems like the data gets jumbled or mixed up. Here's a minimal reproducible example:

library(plotly)

plot_ly(data = iris, x = ~Sepal.Length, y = ~Sepal.Width, color = ~Species, 
        type ="scatter", mode = "markers",text = ~Species,
        hovertemplate = paste('<i>Species</i>: %{text}',
                        '<br><b>X</b>: %{x}<br>',
                        '<b>Y</b>: %{y}')
        
        ) %>%
  layout(
    annotations = list(
      list(
        text = "<b>X-Axis Variable:</b>", x=0.05, y=1.13, 
        xref='paper', yref='paper',xanchor = "left", showarrow=FALSE
      )
    ),
    updatemenus = list(
      list(
        type = "list",
        x = 0.25,
        xanchor = "left",
        y = 1.15,
        buttons = list(
          list(
            method = "update",
            args = list(list(x = list(iris$Sepal.Length)),
                        list(xaxis = list(title = "Sepal.Length"))),
            label = "Sepal.Length"
          ),
          list(
            method = "update",
            args = list(list(x =list(iris$Sepal.Width)),
                        list(xaxis = list(title = "Sepal.Width"))),
            label = "Sepal.Width"
          ),
          list(
            method = "update",
            args = list(list(x = list(iris$Petal.Length)),
                        list(xaxis = list(title = "Petal.Length"))),
            label = "Petal.Length"
          ),
          list(
            method = "update",
            args = list(list(x = list(iris$Petal.Width)),
                        list(xaxis = list(title = "Petal.Width"))),
            label = "Petal.Width"
          )
        )
      )
    )
  )

Which produces a plot that initially looks correct but its behavior is not correct:

We know it's not correct because when we change the x-variable to Sepal.Width, which is the same as the y-variable and therefore should result in a simple line of points along the y=x axis, we're left with the plot below:

There's some talk on SO from questions like this that suggests that selecting a color variable isn't supported with the R-plotly API but I'm not interested in changing the color. Interestingly, this issue disappears when I remove the color = ~Species argument from my plot.

Thanks all - not sure where the best place to look is!

score 1 · Accepted Answer · answered Jul 23 '21 at 14:22

Answering my own question to hopefully help someone else out some point in the future.

As long as you're not interested in a legend, you can actually get around this data plotting issue by mapping the color to the points in the marker argument of plot_ly().

library(plotly)
iris2 <- mutate(iris, iris.col = factor(Species, label = c("red", "blue", "green")))

plot_ly(data = iris2, x = ~Sepal.Length, y = ~Sepal.Width, marker = list(color = ~iris.col), type ="scatter", mode = "markers",text = ~Species,
        hovertemplate = paste('<i>Species</i>: %{text}',
                        '<br><b>X</b>: %{x}<br>',
                        '<b>Y</b>: %{y}')
        
        ) %>%
  layout(
    annotations = list(
      list(
        text = "<b>X-Axis Variable:</b>", x=0.05, y=1.13, xref='paper', yref='paper',xanchor = "left", showarrow=FALSE
      )
    ),
    updatemenus = list(
      list(
        type = "list",
        x = 0.25,
        xanchor = "left",
        y = 1.15,
        buttons = list(
          list(
            method = "update",
            args = list(list(x = list(iris$Sepal.Length)),
                        list(xaxis = list(title = "Sepal.Length"))),
            label = "Sepal.Length"
          ),
          list(
            method = "update",
            args = list(list(x =list(iris$Sepal.Width)),
                        list(xaxis = list(title = "Sepal.Width"))),
            label = "Sepal.Width"
          ),
          list(
            method = "update",
            args = list(list(x = list(iris$Petal.Length)),
                        list(xaxis = list(title = "Petal.Length"))),
            label = "Petal.Length"
          ),
          list(
            method = "update",
            args = list(list(x = list(iris$Petal.Width)),
                        list(xaxis = list(title = "Petal.Width"))),
            label = "Petal.Width"
          )
        )
      )
    )
  )

With the expected output:

R Plotly dropdown variable selection with color

1 Answers1