reopening #4063 New smooth curve causes time to warp for sparse data

[DamienGdn]

I am reopening post #4063 regarding the bug 'New smooth curve causes time to warp for sparse data,' which is still not fixed in ApexChart v3.44.0.

Description

The latest release (3.43.0) changed the "smooth" curve. This is an improvement and looks great for evenly spaced data, but when data is sparse and moves around a lot, it can cause the chart to temporarily flow backwards in time, or completely reverse and do a loop.

Steps to Reproduce

Make a line or area chart with sparse erratic data (for example, [{ x: 0, y: 11 }, { x: 1, y: 10 }, { x: 2, y: 18 }, { x: 13, y: 5 }, { x: 20, y: 100 }])
Set stroke.curve to 'smooth'
Enjoy the show
Expected Behavior
Line and area chart lines move relatively smoothly from one point to the next, but never going backwards in time.

Actual Behavior

Line and area chart lines can go backwards in time.

Screenshots

Reproduction Link
https://codepen.io/Tankenstein/pen/ZEVZXeq

I have the same issue on my side, as you can see.

[azivkovi]

This is still an issue: https://codepen.io/azivkovi/pen/ZEwqOxG

[meixger]

Similar problem with null values and smooth: https://codepen.io/meixger/pen/XWGmaEJ

[mtuzenko]

Same issue here

[junedchhipa]

The previous smooth logic is re-added since v3.45.2

So, from now on, you have 4 curve options for stroke

stroke: {
  curve: "smooth" // straight, smooth, monotoneCubic, stepline
}

Use either smooth or monotoneCubic to see whatever works for you.