position of 0 values with grouped data and positive and negative values

[michkami]

Description

I was working with grouped data in the last days and I noticed something weird.

In this chart I use data.order: null to keep the order of the data as I ordered it manually.

When you look at the image above, I would expect the 0 on the left side to be positioned below the -11 to match the data order.
The -1 on the right side is placed below -11 (at -12) which is what I expect because we cumulate the values below the zero line up to the -1 when they are grouped.
It seems that if there are positive and negative and the value is zero it doesn't cumulate the values below the zero line up to 0 but it cumulates all values (positive and negatives) and that's why the 0 is positioned at -8 instead of the correct accumulated value (-12) on the left side.

Is this the right behaviour or is it a bug?

Steps to check or reproduce

https://jsfiddle.net/michkami/7jn9wq2b/

[netil]

I would expect the 0 on the left side to be positioned below the -11 to match the data order.

IMO, series 3 should stay at the top if data.order=null is specified.

[netil]

@michkami, after doing some approach, doubt on how zero should be represented?

In a scenario, where the example you provided, the series3 value goes from 0 to -1. Looks reasonable the coordinate of 0 staying at the bottom(near -11 at y Axis) as you said, but what if value goes from 0 to 1?

If treat 0 as negative value, and when the value flows from 0 to 1, it needed to be drawn from the bottom to the top as follows.

What I want to explain here is, the 0 can be negative or positive. Look nicer if 0 treated as "negative" when value flows to negative, but is awkward, if flows to positive and vice versa.

This can be proven with example. For example when 0 is treated as "positive" value, representing 0 to 1,

• Will look nicer if value flows to positive value,
  

• But, looks awkward if value flows to negative value.
  

---

So, my idea is, this issue can't be handled automatically. It needs to provide some option to implicitly determine, how 0 will be treated.

• treat as absolute 0
  value 0 won't be stacked, and will correlated with y axis 0.

  • left: 0 to 1 / right: 0 to -1
    

• treat as negative 0 as described above

• treat as positive 0 as described above