Plotly does not show lines

Question

I am using plotly to visualize a dataset into an interactive plot that can be used in a shiny application in a dashboard. I'm using the plotly package as it seems very suitable for me to do something like this. I want to create a plot with lines and markers. When trying to do with a trace using the code below I only get markers and no lines in between

plot_ly(cube_eduexpgdp, x = ~year) %>% 
  add_trace(y = ~expenditure_gdp, mode = "lines+markers",
            color = ~country_name, line = list(shape = "linear")) %>%
  layout(title = "Government expenditures as percentage of GDP", 
          yaxis = list(title = "Expenditures (%)"), 
          xaxis = list(title = "Year"))

This tutorial from plotly suggests to do it with the following code. When I use this code I get an empty canvas that does show the grouped datapoints' values on a tooltip when I hover over it.

plot_ly(cube_eduexpgdp, x = ~year, y = ~expenditure_gdp, 
        color = ~country_name) %>%
  add_lines()  `

Is there anyone that could help me? Would be very much appreciated!

Answer 1

I had the same error and found it was caused by trying to plot a grouped dataframe, so had to ungroup() first. As found here: R - plotly invisible lines

Answer 2

Without a reproducible example, I can only guess here, but it is probably due to inheritance and/or plotly defaults. Does the code below help?

plot_ly(cube_eduexpgdp, x = ~year, type = 'scatter', mode = 'markers') %>% 
  add_trace(y = cube_eduexpgdp[['expenditure_gdp']], mode = "lines+markers",
            color = cube_eduexpgdp[['country_name']], line = list(shape = "linear"), inherit = FALSE) %>%
  layout(title = "Government expenditures as percentage of GDP", 
          yaxis = list(title = "Expenditures (%)"), 
          xaxis = list(title = "Year"))