BoundaryGap

[motassimbakali]

First of all, many thanks for this amazing package!

When creating a line chart, I came across the fact that there is always a gap between the start/end of the line-chart and the x-axis. I found out through Baidu that you can change this by setting boundaryGap to FALSE.

However, I could not get this to work. I tried the following:
mtcars %>% e_charts(wt) %>% e_area(qsec) %>% e_x_axis(boundaryGap = FALSE, min = 1)

Is this not available in the package or did I do something wrong? Thank you!

[JohnCoene]

I cannot reproduce the issue.

Say we plot something clearer first.

df <- data.frame(
  x = 1:10,
  y = 1:10
)
df %>% 
  e_charts(x) %>% 
  e_line(y) %>% 
  e_tooltip(
    trigger = "axis"
  )

You shouldn't see any boundary gap. Now say we plot your example again, but with tighter boundaries to our graph.

min <- min(mtcars$wt)
max <- max(mtcars$wt)

mtcars %>% 
  e_charts(wt) %>% 
  e_area(qsec) %>% 
  e_x_axis(
    min = min,
    max = max
  ) %>% 
  e_tooltip(trigger = "axis")

The documentation for boundaryGap actually states that the parameter works differently for numerical and categorical data:

• For numerical continuous data pass a vector
• For categorical data pass TRUE or FALSE

mtcars %>% 
  e_charts(wt) %>% 
  e_area(qsec) %>% 
  e_x_axis(
    boundaryGap = c("50%", "50%") # add boundary gap
  ) %>% 
  e_tooltip(trigger = "axis")

If you have categorical:

df <- data.frame(
  x = LETTERS[1:4],
  y = runif(4, 1, 3)
)

df %>% 
  e_chart(x) %>% 
  e_bar(y) %>% 
  e_x_axis(
    boundaryGap = FALSE 
  )

So generally speaking you want to use boundaryGap depending on the data you have and the plot you are trying to create.

Let me know if this helps.

[motassimbakali]

Thank you very much for your quick reply! All seems to work very well and I can use the tool_tip as well when using "axis".

However, if I change the e_tooltip to "item" instead of "axis", I do not get the tooltip for the maximum x-value. So for your first example:

df <- data.frame(
  x = 1:10,
  y = 1:10
)
df %>% 
  e_charts(x) %>% 
  e_line(y) %>% 
  e_tooltip(
    trigger = "item"
  )

This doesn't give me a tooltip at x = 10. Do you know what the reason is behind this?

[JohnCoene]

Indeed.

Well this is when you could, for instance, use boundaryGap.

# initialise chart
df <- data.frame(
    x = 1:10,
    y = 1:10
)
df %>% 
    e_charts(x) %>% 
    e_line(y) %>% 
    e_tooltip(
        trigger = "item"
    ) %>% 
    e_tooltip(trigger = "item") -> p

Using boundaryGap - a vector for continuous data, as mentioned above.

p %>% e_x_axis(boundaryGap = c(0, .1))

Or min and max

p %>% e_x_axis(min = 0, max = 12)

And there are probably other ways I'm unaware of.

[motassimbakali]

Thank you very much! I will use that way and close this issue.