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Tag: uniform heatmap

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I am trying to implement a waterfall chart with uniform heatmap. The data is updated from the top of the chart and keeps pushing the old data down. I would like to show the y-axis with time. How can I update the y-axis with updated data?

Assume the heatmap is 256 height, I created the zValues array with min value when draw the heatmap:

const minPower = -200;
spectrogramZValues.current = Array.from(Array(SPECTROGRAM_HEIGHT), () => Array(SPECTROGRAM_WIDTH).fill(minPower));

Update zValues array when new data come:


When the first data pushed to the chart. There will be one row shown in the axis with timestamp t1. When the second data comes, the top row of the y-axis should be t2 and the t1 is pushed down. When the waterfall chart is filled with 256 data, the bottom of the y-axis should be t1 and the top of the y-axis should be t256. Is it possible to implement this?

Now I am using the uniform heatmap to implement it with yStart=0 and yStep=1. I tried to add the labelProvider to the y-axis to show the timestamp of each row. I am keeping an array locally to store the timestamp of each row which will be updated with the new data. I tried to map this array and return the timestamp in the y-axis labelProvider. But it doesn’t work. The y-axis will not be refreshed when data updated.

        yAxis.labelProvider.formatLabel = (dataValue) => {
        const ts = timestampArray[dataValue];
        if (ts) {
            const timeObj = new Date(ts);
            const hours = ('0' + timeObj.getHours()).slice(-2);
            const minutes = ('0' + timeObj.getMinutes()).slice(-2);
            const seconds = ('0' + timeObj.getSeconds()).slice(-2);
            const milliseconds = ('0' + timeObj.getMilliseconds()).slice(-3);
            return `${hours}:${minutes}:${seconds}.${milliseconds}`;
        } else {
            return "";
  • Quyen Sy asked 1 year ago
  • last active 1 year ago
0 votes


I’m building a heatmap with UniformHeatmapRenderableSeries I would like to know if it is possible to get some text inside each block.
I would like to display the block size when I zoom in like this
Do you have any suggestions?

Best Regards,

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