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.
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?
- Quyen Sy asked 7 months ago
- last active 7 months ago
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();
- Quyen Sy asked 7 months ago
- last active 7 months ago
I am using UniformHeatMapDataSeries to plot a heat map in WPF/C#. However, the data is very large in size and as a result it is throwing OutOfMemoryException while populating the first parameter value of this data series. which is a two dimensional array TZ (generic).
As per definition:
public UniformHeatmapDataSeries(TZ[,] zValues, TX xStart, TX xStep, TY yStart, TY yStep, IPointMetadata[,] metadata = null);
Here I am filling this array with double[,] data.
This error is happening due to TZ double[,] is filled with very big size of data going out of max defined range of double 2D array size. Please suggest if I can replace the values of double[,] with any other data type which allow larger data.
- Anil Soman asked 3 years ago
- last active 3 years ago
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 years ago
- last active 4 years ago
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!
- Ryan Fessler asked 4 years ago
- last active 4 years ago
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).
- Gia D. asked 5 years ago
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?
- MIha Rozina asked 5 years ago
- last active 5 years ago