Tag: LogarithmicNumericAxis

I think this question has come up before, but is it possible to render a logarithmic axis in the JS library? If not, is this on the roadmap (and when)?

Hi,

Using a tooltip with a LineSeries with an Logarithmic Y-axis, seem to give widely inaccurate results.

The series is as follows:

double[] x = new double[] { 1, 1.0e1 , 1.0e2 };
double[] y = new double[] { 615.9, 275.6197, 11.05376};

Using a CursorModifier as follows:

<s:CursorModifier ShowAxisLabels="True" UseInterpolation="True" SnappingMode="CrosshairToSeries" ShowTooltip="True"/>

The expected behaviour would be for the Crosshair to follow the curve, but for some reason it’s some way off. It looks as if it’s following Y-values which are somewhat truncated. X-values are fine for some reason.

Is there are a way to increase the resolution of the Y-values so the user gets the correct value when using a tooltip.

If you change the logarithmic Y axis to a regular NumericalAxis, the mountain series displays properly (with fill color).

I’m seeing the following exception:

E/Exception: null
    java.lang.ArrayIndexOutOfBoundsException: length=0; index=-1
        at com.scichart.core.model.DoubleValues.get(SourceFile:167)
        at com.scichart.charting.numerics.tickProviders.LogarithmicNumericTickProvider.updateTicks(SourceFile:94)
        at com.scichart.charting.numerics.tickProviders.TickProvider.update(SourceFile:59)
        at com.scichart.charting.numerics.tickProviders.DeltaTickProvider.update(SourceFile:81)
        at com.scichart.charting.visuals.axes.AxisBase.onUpdateMeasure(SourceFile:957)
        at com.scichart.charting.visuals.axes.AxisBase.updateAxisMeasurements(SourceFile:936)
        at com.scichart.charting.layoutManagers.RightAlignmentOuterAxisLayoutStrategy.measureAxes(SourceFile:39)
        at com.scichart.charting.layoutManagers.DefaultLayoutManager.onLayoutChart(SourceFile:235)
        at com.scichart.charting.visuals.rendering.RenderSurfaceRenderer.a(SourceFile:207)
        at com.scichart.charting.visuals.rendering.RenderSurfaceRenderer.a(SourceFile:132)
        at com.scichart.charting.visuals.rendering.RenderSurfaceRenderer.onDraw(SourceFile:123)
        at com.scichart.drawing.opengl.RenderSurfaceGL$a.onDraw(SourceFile:234)
        at com.scichart.drawing.opengl.MyGLRenderer.b(SourceFile:299)
        at com.scichart.drawing.opengl.MyGLRenderer.onDrawFrame(SourceFile:283)
        at android.opengl.GLSurfaceView$GLThread.guardedRun(GLSurfaceView.java:1571)
        at android.opengl.GLSurfaceView$GLThread.run(GLSurfaceView.java:1270)

I’m initializing my chart as follows:

SciChartBuilder.init(context)
builder = SciChartBuilder.instance()

...

val xAxis = builder.newCategoryDateAxis()
                            .withGrowBy(0.0, 0.05)
                            .withAxisAlignment(AxisAlignment.Bottom)
                            .withVisibleRange(sharedXRange)
                            .withDrawMinorGridLines(true)
                            .withDrawMajorGridLines(true)
                            .build()
val yAxis = builder.newLogarithmicNumericAxis()
                            .withTextFormatting("#.#E+0")
                            .withScientificNotation(ScientificNotation.LogarithmicBase)
                            .withLogarithmicBase(2.0)
                            .build()
val seriesData = builder.newXyDataSeries(Date::class.java, Double::class.javaObjectType)
                            .withSeriesName("Series A")
                            .build()
seriesData.append(data.dateData, data.yData)
series = builder.newLineSeries()
                            .withDataSeries(seriesData)
                            .build()

UpdateSuspender.using(surface) {
                Collections.addAll(surface.xAxes, xAxis)
                Collections.addAll(surface.yAxes, yAxis)
                Collections.addAll(surface.renderableSeries, series)
}

data object has about 300 valid data points.

Any ideas what’s going on? I tried running this on a new activity. If I swap LogarithmicNumericAxis for a NumericAxis, everything works fine. I looked at the decompiled .class file where the crash was occurring (I don’t have the source for SciChart), and it seems like the crash occurs when major ticks fail to get generated (majorTicks.size == 0). I tried disabling all minor/major ticks but no joy.

for(int var22 = majorTicks.size(); var22 >= 0; --var22) {
            double var23 = var4.fromExponent(var11);
            double var25 = var22 < majorTicks.size() ? majorTicks.get(var22) : majorTicks.get(var22 - 1) * var23;

Hi

I was trying to bind DoubleRange type property to the VisibleRange property of LogarimethicNumericAxis.
Since DoubleRange is not a primitive type, OnPropertyChanged command didn’t work in c#.
Is there any way to reslove this problem?
My code is as below.

in View

<sci:SciChartSurface.XAxis>
    <sci:LogarithmicNumericAxis AutoRange="Never"    
        DrawMajorGridLines="False" 
        DrawMinorGridLines="False" 
        DrawMajorBands="False"
        Visibility="Visible"
        VisibleRange="{Binding Path=AxisVisibleRange,Mode=OneWay, UpdateSourceTrigger=PropertyChanged}">
    </sci:LogarithmicNumericAxis>
</sci:SciChartSurface.XAxis>

in View model

public DoubleRange AxisVisibleRange
{
    get
    {

        DoubleRange dr = new DoubleRange(0.1,100);
        return dr;

    }
}        

Hi !

Does the android version of SciChart feature logartihmic axis scaling ?

I’m trying to use LogarithmicNumericAxis for y-axis. But when chart has a small range of values (for a example, from 32 to 41) the axis became a empty.