Get visible points for a series in LightningChartJs

user_3765577 0
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Exists a function in LightningChartJs to get all visible points from a line or point series in a chart?

If I zoom the chart I want to show something if no visible points available. In some cases I have breaks in my data.

For now I have to check the range and filter all points within this range, but that seems not to be very performant. I guess LC is aware of all the visible points and can give me that.

I would very much welcome any thoughts on the subject or other solutions. Thanks.

lightningchart charts javascript
1 Answers

LightningChart JS doesn't track the data points that are visible at any time. So the method that you have used to solve the issue is the best way currently.

Something like this seems to be reasonably performant.

function getDataInRange(data, rangeStart, rangeEnd){
    const inRangeData = []
    const dataLength = data.length
    let curPoint
    for(let i = 0; i < dataLength; i += 1){
        curPoint = data[i]
        if(curPoint.x >= rangeStart && curPoint.x <= rangeEnd){
            inRangeData.push(curPoint)
        }
    }
    return inRangeData
}

On my personal machine it can process 1 million points in ~10ms ± 2ms. If you only want to know that a point is visible in the range then you could just break the loop as soon as a single point is in the visible range.

user_61982270
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