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I am not able to find the data point corresponding to current mouse position on heatmap series PreviewMouseMove event.

Here is my code,

private void Contour_PreviewMouseMove(object sender, MouseEventArgs e)
    {
        var xCalc = Contour.RenderableSeries[0].XAxis.GetCurrentCoordinateCalculator();
        var yCalc = Contour.RenderableSeries[0].YAxis.GetCurrentCoordinateCalculator();
        Point mousePoint = e.GetPosition(((SciChartSurface)sender).ModifierSurface as UIElement);
        double peakXCordInfoValue = xCalc.GetDataValue(mousePoint.X);
        double peakYCordInfoValue = yCalc.GetDataValue(mousePoint.Y);
    }

“Contour” is my SciChart object. When I debugged to find out my X and Y axis data points and compared them with what I find above in peakXCordInfoValue, then they don’t match. Ideally if I am finding the data point then it should match exactly.

I also tried to find index

var index = Contour.RenderableSeries[0].DataSeries.FindIndex(yDataForCoordinate, SearchMode.Nearest);

But it gives error “Operation is not valid due to the current state of the object.”
I also tried cursormodifier and its OnModifierMouseMove event, but it gives same error.

For Example: The actual data point on Y axis is 280.774501562118, and the above code returns 280.523009343212

  • Anil Soman asked 4 months ago
  • last active 4 months ago
0 votes
374 views

Currently, I’m using a uniform heatmap to display images taken from a monochrome camera. I’m using a RubberBandXyZoomModifier to allow to user to zoom in on a region of interest in the image. The SciChartSurface is set to be 640×480 (the image size) and is hosted in a Viewbox, so it’s size scales uniformly with the grid that it’s in. The problem I’m facing is that when I zoom in, the zoomed part of the image stretches to fit the 640×480 size, changing the pixel aspect ratio, but I want the pixel aspect ratio to stay constant so they are all square. What I want to happen is that extra space is added either on the top/bottom or left/right of the zoomed part of the image so the pixel aspect ratio stays constant. See the attached image for a visual explanation. I think I either need to change the SciChartSurface size or the GridLinesPanel size to match the zoomed area size, but I’m not sure how to go about doing that. Is there a way to achieve this? Thanks!

0 votes
0 answers
2k views

Hi,

I am playing with the heatmap chart and stumbled upon an IndexOutOfRange exception when updating the chart.

I initialise my chart where Height=2 and Width=3:

var data = new double[Height, Width]; // 2 rows, 3 columns
double d = 0.0;
for (int y = 0; y < Height; y++)
{
    for (int x = 0; x < Width; x++)
    {
        data[y, x] = d++;
    }
}

heatmapSeries.DataSeries = new UniformHeatmapDataSeries<int, int, double>(data, 0, 1, 0, 1);

Calling the following line returns 5 which is equivalent to getting the value with data[1,2] (all good so far):

dataseries.GetZValue(yIndex: 1, xIndex: 2);

Now let’s update that value to, say 7.1, with:

dataseries.UpdateZValue(xIndex: 2, yIndex: 1, zValue: 7.1);

Executing the above line throws an IndexOutOfRangeException. Looking at the source code, the UpdateZValue() method does:

_zValues[xIndex, yIndex] = zValue;
// ...

No wonder why the exception gets thrown… I reckon it should be _zValues[yIndex, xIndex] = zValue; (xIndex and yIndex swapped).

0 votes
2k views

Is it possible to grow a UniformHeatmapDataSeries in the x direction? It only has methods to update the Z values. I have a case where X axis represents time and I need to keep adding values in X direction. Is there a way to do it besides recreating UniformHeatmapDataSeries with new values?

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