How to hover number formatting to K or M accordingly in R Plotly pie charts and line charts

Question

Hi I am trying to plot a pie chart in R plotly for my shiny app where I want to format hover numbers to K or M but couldn't the correct solution for that Here is a reproducible code that I am using, any help would be appreciated

full_data<-data.frame("Name"=c("Q1","Q1","Q2","Q2","Q3","Q3"),"Values"=c(245645,866556,26440,65046,641131,463265))

desc<-full_data%>%group_by(Name)%>%summarise(values=sum(Values))

fig<-plot_ly(desc,labels=~Name,values=~values,type = "pie",
             insidetextfont = list(color = 'white'),
             marker = list(colors = colors,
                           line = list(color = '#FFFFFF', width = 1),hoverformat = ',.0f'))%>%
  layout(title = list(text='<b> Volume(lbs.) </b>',x=0,y=1,titlefont=20),
         font=list(family="Corbel",size=15,color="rgb(33,33,33"),
         xaxis = list(showgrid = FALSE, zeroline = FALSE, showticklabels = FALSE),
         yaxis = list(showgrid = FALSE, zeroline = FALSE, showticklabels = FALSE),
         legend=list(font=list(size=18)),
         margin = list(pad = 10,t=60))

fig

Here you can see hover number is 1,112,201 what I want this as 1.1M or if the number is less than a million let's say the number is 125,463 then it should be 125.5K while we hover over the pie chart

Thank you in advance

It is not clear to me what the desired output it? could you explain what "format hover numbers to K or M" means? — missuse, Oct 12 '20 at 07:15
Perhaps this will help: https://stackoverflow.com/questions/28159936/format-numbers-with-million-m-and-billion-b-suffixes. The answer `scales::label_number_si` seems particulary easy to use. — missuse, Oct 12 '20 at 07:44
I would have gone with that but the problem for me is in the hovering if numbers need to be displayed other than chart then this would be the perfect solution — Sumit Kumar, Oct 12 '20 at 07:50

missuse · Accepted Answer · 2020-10-12T08:34:27.537

To achieve a custom hover label you can supply a vector to customdata argument with the desired formatting and define the appropriate hovertemplate.

To get the desired formatting you can use scales::label_number_si:

library(plotly)

desc <- full_data %>% 
  group_by(Name) %>% 
  summarise(values = sum(Values)) %>%
  mutate(lab = scales::label_number_si(accuracy = 0.1)(values))

desc
# A tibble: 3 x 3
  Name   values lab  
  <chr>   <dbl> <chr>
1 Q1    1112201 1.1M 
2 Q2      91486 91.5K
3 Q3    1104396 1.1M 

plot_ly(desc,
        customdata = desc$lab, #pass the lab vector
        labels = ~Name,
        values = ~values,
        type = "pie",
        insidetextfont = list(color = 'white'),
        marker = list(colors = colors,
                      line = list(color = '#FFFFFF', width = 1),
                      hoverformat = ',.0f'),
        hovertemplate = "%{label} <br> %{customdata} <br>  %{percent}") #define hovertemplate

this works too:

plot_ly(desc,
        customdata = ~lab,
        labels = ~Name,
        values = ~values,
        type = "pie",
        insidetextfont = list(color = 'white'),
        marker = list(colors = colors,
                      line = list(color = '#FFFFFF', width = 1),
                      hoverformat = ',.0f'),
        hovertemplate = "%{label} <br> %{customdata} <br>  %{percent}")

To remove the annoying trace 0 in the hover add <extra></extra>:

plot_ly(desc,
        customdata = ~lab,
        labels = ~Name,
        values = ~values,
        type = "pie",
        insidetextfont = list(color = 'white'),
        marker = list(colors = colors,
                      line = list(color = '#FFFFFF', width = 1),
                      hoverformat = ',.0f'),
        hovertemplate = "%{label} <br> %{customdata} <br>  %{percent} <extra></extra>")

In [python customdata can be an array](https://chart-studio.plotly.com/~empet/15366/customdata-for-a-few-plotly-chart-types/#/). However in R a vector is the only possibility. This [workaround](https://github.com/ropensci/plotly/issues/1548) might come in handy, but I could not make it work. — missuse, Oct 12 '20 at 10:12

How to hover number formatting to K or M accordingly in R Plotly pie charts and line charts

1 Answers1