Ticktext doesn't show for some numerical values in parallel coordinates plotting.

[YangVincent]

Currently, I am trying to plot categorical variables in plotly. I run this

(This has incorrect result)

library(plotly)

p <- plot_ly(type = 'parcoords', line = list(color = 'blue'),
             dimensions = list(
               list(range = c(1,5),
                    constraintrange = c(1,2),
                    label = 'A', values = c(1,4)),
               list(range = c(1,5),
                    tickvals = c(1.5,3,4.5),
                    label = 'B', values = c(3,1.5)),
               list(range = c(1,2),
                    tickvals = c(1,2),
                    label = 'C', values = c(2,4),
                    ticktext = c('0','1')),

               list(range = c(1,5),
                    label = 'D', values = c(4,2))
               )
             )
p

and this: (this has correct, expected result)

library(plotly)

p <- plot_ly(type = 'parcoords', line = list(color = 'blue'),
             dimensions = list(
               list(range = c(1,5),
                    constraintrange = c(1,2),
                    label = 'A', values = c(1,4)),
               list(range = c(1,5),
                    tickvals = c(1.5,3,4.5),
                    label = 'B', values = c(3,1.5)),
               list(range = c(1,2),
                    tickvals = c(1,2),
                    label = 'C', values = c(2,4),
                    ticktext = c(' 0 ',' 1 ')),

               list(range = c(1,5),
                    label = 'D', values = c(4,2))
               )
             )
p

Notice that the only change is the 3rd ticktext. With spaces, it works correctly but without, it doesn't. Swapping the ('0', '1') out with ('1', '2') or ('male', 'female') also works correctly.

Expected behavior: There should be a 0 label at the bottom and 1 at the top.
Actual behavior: The top label is missing.

[cpsievert]

@monfera would you a plotly.js-ified version of this issue?