ValueAxis QML Type, Y axis Auto Fit!!

? Offline

I had a dynamic chart now! with QML

But how to make the ValueAxis (for y axis) to automatically fit the the plotted data through ChartView!

I tried to get the chart data and store it in an array, then check the max and min inside the array, but it looks complicated for me and I can't even look inside the array!

Any advice!

SeeLook

Hi,

Probably You may use scale prop for it.
Just track lowest and highest values as they come in real time and when a span between them changes - adjust the scale.

kumarv

Check the solution given in the following link
https://stackoverflow.com/questions/44940190/qtcharts-auto-range-for-y-axis
P.S. Chart is created using Cpp.

neda

Hi,
Why don't you use the following example?
https://forum.qt.io/topic/77439/can-someone-provide-a-working-example-of-vxymodelmapper-with-lineseries-chart/2

void ChartModel::appendData(double const xVal,double const yVal)
{
    setXMin(qMin(m_xMin, xVal));
    setXMax(qMax(m_xMax, xVal));
    setYMin(qMin(m_yMin, yVal));
    setYMax(qMax(m_yMax, yVal));
    int const vecSize = vecChartPoints.size();
    beginInsertRows(QModelIndex (), vecSize, vecSize);
    vecChartPoints.append(qMakePair<double, double>(xVal, yVal));
    endInsertRows();
}

ValueAxis {
                            id: valueAxisY
                            min: chartModel.yMin
                            max: chartModel.yMax
                            labelFormat: "%.2f"
                        }