Tag: javascript

I am implementing a heatmap. The data size of the heatmap would be changed. When the data size changed, I will replace the zValues of the UniformHeatmapDataSeries with an updated array. But it doesn’t work for me. The heatmap data cannot be plotted after I updated the zValues array. Below are my codes to create the heatmap and update the zValues array.

Draw heatmap:

    const { sciChartSurface, wasmContext } = await SciChartSurface.create("spectrogram-chart-root");
    let xAxisNumberRange = new NumberRange(minFreq/maxFreq);

    spectrogram_xAxis.current = new NumericAxis(wasmContext, {
        axisTitle: "Frequency",
        axisTitleStyle: {
            fontSize: CHART_STYLE.AXIS_FONT_SIZE,
            fontFamily: "sans-serif",
            fontWeight: "bold"
        },
        labelStyle: {
            fontSize: CHART_STYLE.LABEL_FONT_SIZE,
            fontFamily: "sans-serif"
        },
        visibleRange: xAxisNumberRange,
        visibleRangeLimit: xAxisNumberRange,
        zoomExtentsRange: xAxisNumberRange,
        labelFormat: ENumericFormat.Decimal,
        labelPrecision: 2,
        cursorLabelFormat: ENumericFormat.Decimal,
        cursorLabelPrecision: 2,
        drawMajorBands: false,
    });

    // Add XAxis and YAxis
    sciChartSurface.xAxes.add(spectrogram_xAxis.current);
    sciChartSurface.yAxes.add(new NumericAxis(wasmContext, { isVisible: false }));

    // Create a Heatmap Data-series. Pass heatValues as a number[][] to the UniformHeatmapDataSeries
    spectrogramZValues.current = Array.from(Array(SPECTROGRAM_HEIGHT), () => Array(SPECTROGRAM_WIDTH).fill(-200));
    heatmapDataSeries.current = new UniformHeatmapDataSeries(wasmContext, {
        xStart: 0,
        xStep: 1,
        yStart: 0,
        yStep: 1,
        zValues: spectrogramZValues.current
    });

    colorMap.current = new HeatmapColorMap({
        minimum: -200,
        maximum: -50,
        gradientStops: gradientStopsArr.current
    });

    // Create a Heatmap RenderableSeries with the color map. ColorMap.minimum/maximum defines the values in
    // HeatmapDataSeries which correspond to gradient stops at 0..1
    const heatmapSeries = new UniformHeatmapRenderableSeries(wasmContext, {
        dataSeries: heatmapDataSeries.current,
        useLinearTextureFiltering: true,
        isSorted: true, 
        isEvenlySpaced: true, 
        containsNaN: false,
        colorMap: colorMap.current
    });

    // Add heatmap to the chart
    sciChartSurface.renderableSeries.add(heatmapSeries);

Update heatmap data:

        // Update the chart x-axis
        if (xAxisUpdateRequired) {
            let xAxisNumberRange = new NumberRange(newStartFreq, newStopFreq);
            spectrogram_xAxis.current.visibleRange = xAxisNumberRange;
            spectrogram_xAxis.current.visibleRangeLimit = xAxisNumberRange;
            spectrogram_xAxis.current.zoomExtentsRange = xAxisNumberRange;  

            // Reset the heatmap zValues
            heatmapDataSeries.current.clear();
            spectrogramZValues.current = Array.from(Array(SPECTROGRAM_HEIGHT), () => Array(newSampleSize).fill(-200));
            heatmapDataSeries.current.setZValues(spectrogramZValues.current);
        }
        // Update heatmap data
        spectrogramZValues.current.shift();
        spectrogramZValues.current.push(newSpecData);
        heatmapDataSeries.current.notifyDataChanged();

I am implementing a heatmap. The data size of the heatmap would be changed. I update the UniformHeatmapDataSeries with the updated zValues according to this post.

https://www.scichart.com/questions/js/failed-to-update-the-zvalues-size-of-uniformheatmapdataseries-in-heatmap

There is no problem if I update the UniformHeatmapDataSeries with a larger size zValues array. However, when I update it with a smaller size zValues array, the heatmap width will be decrease (Please refer to my screenshots). How can I keep the heatmap always 100% width?

I want to create two xAxis, the first one will be a normal xAxis and the second one will be an array of date ranges, but the issue then is that since all the xAxis are inside one array together, they all are stacked on top of each other.

I tried sciChartSurface.layoutManager.bottomOuterAxesLayoutStrategy = new BottomAlignedOuterHorizontallyStackedAxisLayoutStrategy(); but that only create all xAxis into one line of xAxis.

I want two line of xAxis, where the first one is normal, but second xAxis should be Horizontally Stacked Axis Layout.

The first image is before horizontal stacked is applied and the second after.

The third image show the xAxes array from sciChartSurface.xAxes, the index(0) of the array is the first xAxis, which should be normal, and the rest (index 1 – 8) should be horizontally stacked.

The horizontal stacked xAxis should be right below the first xAxis.

I am using the solution you provided on, https://www.scichart.com/questions/js/is-it-possible-to-create-info-box-that-will-sync-with-the-xaxis-of-the-chart.

The solution work great but there is one issue, the issue is that the text annotation should always be visible.

The issue with this solution is that the text annotation disappear if I zoom in somewhere not the text area.

Also another issue is that, in this example, the first info box x1 is beyond the current range, and so the text annotation is not visible, since the x1 of the text annotation is the same as info box and x1 is not within the current range.

First image show the first red info box x1 is not within current range, therefore not showing text annotation and the second info box working as expected with text annotation.

The second image show what happen once I zoom in on the right side away from the text annotation, then the ‘#21H’ is not visible anymore, which is wrong. Just like in my previous question example, the text annotation should always be visible, other than that, everything work great.

Thank you and let me know if there is any question.

As if right now, I have create a custom annotation, which is a red circle and the idea is to show some info when hovering on it, like a tooltip.

Right now, when hovering on the red circle, I am adding another custom annotation to show the info and then removing it when not hovering anymore. The issue with this is that it is not very stable, as in if I don’t point my cursor right in the middle of the red circle, it won’t register as hit. I tried putting hitTestRadius to 50 on CursorModifier, but doesn’t seem to make any difference.

I have also try with xyScatterRenderableSeries and EllipsePointMarker, the issue I find with it is that it is interfering with my data series tooltip, as the cursor modifier recognize it as a chart series and try to show on the tooltip, which I don’t want. I only want the red circle to be trigger only when cursor is right on it.

The first image is my code and how I am trying to achieve it at the moment, it does work, but I don’t think it’s very stable, I wish there is a more natural way to do it.

The second image is how my current solution looks like, as you can see, the data series tooltip is overlapping it, which I want to avoid. I can’t think of a way to solve the overlapping issue yet. Other than unstableness and the tooltip overlapping, it work fine.

The third image is how I want it to look like.

Hi, so I need to get the data of an annotation when clicked, I have tried with addEventListener ‘mousedown’ event and it work for most case, but the issue comes when some annotations are overlapping.

codesandbox example: https://codesandbox.io/s/vertically-stacked-axes-forked-smkd8v?file=/src/App.tsx

In the codesandbox example, you will see that M1 and M2 are overlapping, if I were to click on M2, the click event will return both M1 and M2, but I only want M2 to be return since I only click on M2.

I couldn’t make the clicking to work on codesandbox but I’m sure you get the idea. I have tested it on my local and I got that issue.

Please let me know if you got any other question, thank you.

I want to be able to disable a chart if there is no data on it, and then enable the chart when there is data. The reason why I want to do that is because I have three charts that are sync and I want to disable the other charts that have no data, so that the cursor modifier or the zooming and stuff will not affect the other charts without data and will only affect the one with data.

Attached image is 3 charts that are in sync.

Hi, I want to create info boxes between xAxis and chart, info box will contain text, but the width/position of the box will be base on the xAxis and should sync with the chart (zoom etc). For example, if xAxis is from 1-100, and the first info box start from 1 to 10, then the width/position of the box should cover from 1-10, and if I zoom between 1-10, then info box should also sync and expand.

So far, I have created it using horizontal stacked xAxes and custom axis layout strategy provided by you. But the issue is that the stacked xAxes are not sync with the chart, for now, to make it seem sync, I am recalculating stacked axis length when zoom. But the issue comes when there should be gap between the info boxes, for example, if xAxis is 1-100 and the first box is 1-10 and the second box is 20-40, then there is a gap of 10 between the first and second. Right now, those gap are filled using empty xAxes, but they are not correct. When there is gap, the position of the boxes are wrong.

• First image is my current implementation of it using custom axis layout and stacked xAxes.
• Second image is how it look when zoomed
• Third image is the gap issue with the current implementation
• Fourth image is how the correct implementation should look like.

Codesanbox example:
https://codesandbox.io/s/scichart-stacked-xaxis-stacked-length-issue-3knt23?file=/src/App.tsx

I want to use a different color for each value in the chart I created here. To put it simply, if the value is greater than 10, I want it to appear yellow, if it is less than green, and red if it is less than 0. thanks

const { sciChartSurface, wasmContext } = await SciChartSurface.create("scichart-root", {
    theme: new SciChartJSLightTheme(),   
});
sciChartSurface.applyTheme(new SciChartJSLightTheme());
sciChartSurface.xAxes.add(new NumericAxis(wasmContext));
sciChartSurface.yAxes.add(new NumericAxis(wasmContext));
const yAxis = sciChartSurface.yAxes.get(0);
yAxis.visibleRange = new NumberRange(LAL, UAL);
const xAxis = sciChartSurface.xAxes.get(0);
xAxis.visibleRange = new NumberRange(0, endBarIndex);

const dataSeries = new OhlcDataSeries(wasmContext, {
    xValues: xValues,
    openValues: yValues,
    highValues: compositeScanAverageArray,
    lowValues: yValues,
    closeValues: compositeScanAverageArray,
});
const renderableSeries = new FastCandlestickRenderableSeries(wasmContext, {
    dataSeries,
    stroke: "white",
    strokeThickness: 1,
});

sciChartSurface.renderableSeries.add(renderableSeries);
sciChartSurface.annotations.add(
    new SciChart.BoxAnnotation({
        stroke: "yellow",
        strokeThickness: 1,
        fill: "rgba(255, 255, 0, 0.3)",
        x1: 0,
        x2: endBarIndex,
        y1: UAL,
        y2: UWL,
    })
);
sciChartSurface.annotations.add(
    new SciChart.BoxAnnotation({
        stroke: "yellow",
        strokeThickness: 1,
        fill: "rgba(255, 255, 0, 0.3)",
        x1: 0,
        x2: endBarIndex,
        y1: LAL,
        y2: LWL,
    })
);
sciChartSurface.annotations.add(
    new SciChart.BoxAnnotation({
        stroke: "green",
        strokeThickness: 1,
        fill: "rgba(0, 128, 0, 0.3)",
        x1: 0,
        x2: endBarIndex,
        y1: LWL,
        y2: UWL,
    })
);
sciChartSurface.annotations.add(
    new SciChart.LineAnnotation({ stroke: "#FF6600", strokeThickness: 3, x1: startBarIndex, x2: endBarIndex, y1: compositeScanAverage, y2: compositeScanAverage }),
);

sciChartSurface.chartModifiers.add(new MouseWheelZoomModifier());
sciChartSurface.chartModifiers.add(new ZoomPanModifier());

}