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

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.

首先运行 issue 中的两个 R plot_ly parcoords 示例，并比较有空格和无空格时的 ticktext 值。从该入口点追踪平行坐标刻度标签的处理；当两个数字标签（包括顶部的 1）都能在未添加空格的情况下渲染时，即表示完成。