This example demonstrates iOS Charts with X or Y logarithmic axis using SciChart.iOS.

The SCILogarithmicNumericAxis type can be set on the XAxis or YAxis of the SCIChartSurface in order to add a logarithmic scale to an iOS chart.

The Logarithmic Base may be set as a double value to change the Logarithmic Base of the axis, e.g. Log10, LogE, Log2.

Axis labels are formatted using Scientific notation with Superscript.

// SCSLogarithmicAxisChartView.swift

//
//  SCSLogarithmicAxisChartView.swift
//  SciChartSwiftDemo
//
//  Created by Yaroslav Pelyukh on 4/5/17.
//  Copyright © 2017 SciChart Ltd. All rights reserved.
//


import Foundation
import SciChart


class SCSLogarithmicAxisChartView: UIView {
    let surface = SCIChartSurface()
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        completeConfiguration()
    }
    
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        completeConfiguration()
    }
    
    func addDefaultModifiers() {
        
        let xAxisDragmodifier = SCIXAxisDragModifier()
        xAxisDragmodifier.dragMode = .scale
        xAxisDragmodifier.clipModeX = .none
        
        let yAxisDragmodifier = SCIYAxisDragModifier()
        yAxisDragmodifier.dragMode = .pan
        
        let extendZoomModifier = SCIZoomExtentsModifier()
        
        let pinchZoomModifier = SCIPinchZoomModifier()
        
        let rolloverModifier = SCIRolloverModifier()
        rolloverModifier.style.tooltipSize = CGSize(width: 200, height: CGFloat.nan)
        
        let groupModifier = SCIChartModifierCollection(childModifiers: [xAxisDragmodifier, yAxisDragmodifier, pinchZoomModifier, extendZoomModifier, rolloverModifier])
        
        surface.chartModifiers = groupModifier
    }
    
    // MARK: initialize surface
    fileprivate func addSurface() {
        surface.translatesAutoresizingMaskIntoConstraints = true
        surface.frame = bounds
        surface.autoresizingMask = [.flexibleHeight, .flexibleWidth]
        addSubview(surface)
    }
    
    // MARK: Overrided Functions
    
    func completeConfiguration() {
        addSurface()
        addAxes()
        addSeries()
    }
    
    // MARK: Private Functions
    
    fileprivate func addAxes() {
        let xAxis = SCILogarithmicNumericAxis()
        xAxis.growBy = SCIDoubleRange(min: SCIGeneric(0.1), max: SCIGeneric(0.1))
        surface.xAxes.add(xAxis)

        let yAxis = SCILogarithmicNumericAxis()
        yAxis.growBy = SCIDoubleRange(min: SCIGeneric(0.1), max: SCIGeneric(0.1))
        surface.yAxes.add(yAxis)
    }
    
    fileprivate func addSeries() {
        let dataSeries1 = SCIXyDataSeries(xType: .float, yType: .float)
        let dataSeries2 = SCIXyDataSeries(xType: .float, yType: .float)
        let dataSeries3 = SCIXyDataSeries(xType: .float, yType: .float)
        
        SCSDataManager.getExponentialCurve(data: dataSeries1, count: 100, exponent: 1.8)
        SCSDataManager.getExponentialCurve(data: dataSeries2, count: 100, exponent: 2.25)
        SCSDataManager.getExponentialCurve(data: dataSeries3, count: 100, exponent: 3.59)
        
        let renderSeries1 = SCIFastLineRenderableSeries()
        renderSeries1.dataSeries = dataSeries1
        renderSeries1.strokeStyle = SCISolidPenStyle(colorCode: 0xFFFFFF00, withThickness: 1.5)
        renderSeries1.style.pointMarker = getPointMarker(size: 5, color: 0xFFFFFF00)
        
        let renderSeries2 = SCIFastLineRenderableSeries()
        renderSeries2.strokeStyle = SCISolidPenStyle(colorCode: 0xFF279B27, withThickness: 1.5)
        renderSeries2.dataSeries = dataSeries2
        renderSeries2.style.pointMarker = getPointMarker(size: 5, color: 0xFF279B27)
        
        let renderSeries3 = SCIFastLineRenderableSeries()
        renderSeries3.strokeStyle = SCISolidPenStyle(colorCode: 0xFFFF1919, withThickness: 1.5)
        renderSeries3.dataSeries = dataSeries3
        renderSeries3.style.pointMarker = getPointMarker(size: 5, color: 0xFFFF1919)
        
        surface.renderableSeries.add(renderSeries1)
        surface.renderableSeries.add(renderSeries2)
        surface.renderableSeries.add(renderSeries3)
        
        
    }
    
    fileprivate func getPointMarker(size:Int, color:UInt)->SCIEllipsePointMarker{
        let ellipseMarker = SCIEllipsePointMarker()
        ellipseMarker.strokeStyle = SCISolidPenStyle(colorCode: 0xFFFFFFFF, withThickness: 0.0)
        ellipseMarker.width = Float(size)
        ellipseMarker.height = Float(size)
        ellipseMarker.fillStyle = SCISolidBrushStyle(colorCode: UInt32(color))
        return ellipseMarker
    }
}

// LogarithmicAxisChartView.m

//
//  LogarithmicAxisChartView.m
//  SciChartDemo
//
//  Created by Yaroslav Pelyukh on 4/5/17.
//  Copyright © 2017 ABT. All rights reserved.
//

#import "LogarithmicAxisChartView.h"
#import "DataManager.h"

@implementation LogarithmicAxisChartView


@synthesize surface;

-(void) createBandRenderableSeries{
    SCIXyDataSeries *dataSeries1 = [[SCIXyDataSeries alloc]initWithXType:SCIDataType_Double YType:SCIDataType_Double];
    SCIXyDataSeries *dataSeries2 = [[SCIXyDataSeries alloc]initWithXType:SCIDataType_Double YType:SCIDataType_Double];
    SCIXyDataSeries *dataSeries3 = [[SCIXyDataSeries alloc]initWithXType:SCIDataType_Double YType:SCIDataType_Double];
    
    [DataManager getExponentialCurve:dataSeries1 cound:100 exponent:1.8];
    [DataManager getExponentialCurve:dataSeries2 cound:100 exponent:2.25];
    [DataManager getExponentialCurve:dataSeries3 cound:100 exponent:3.59];
    
    SCIFastLineRenderableSeries * lineSeries1 = [[SCIFastLineRenderableSeries alloc] init];
    [lineSeries1 setDataSeries:dataSeries1];
    [lineSeries1 setStrokeStyle:[[SCISolidPenStyle alloc]initWithColorCode:0xFFFFFF00 withThickness:1.5]];
    [lineSeries1.style setPointMarker:[self getPointMarkerWithSize:5 colorCode:0xFFFFFF00]];
    
    SCIFastLineRenderableSeries *lineSeries2 = [SCIFastLineRenderableSeries new];
    [lineSeries2 setDataSeries:dataSeries2];
    [lineSeries2 setStrokeStyle: [[SCISolidPenStyle alloc]initWithColorCode:0xFF279B27 withThickness:1.5]];
    [lineSeries2.style setPointMarker:[self getPointMarkerWithSize:5 colorCode:0xFF279B27]];
    
    SCIFastLineRenderableSeries *lineSeries3 = [SCIFastLineRenderableSeries new];
    [lineSeries3 setDataSeries:dataSeries3];
    [lineSeries3 setStrokeStyle: [[SCISolidPenStyle alloc]initWithColorCode:0xFFFF1919 withThickness:1.5]];
    [lineSeries3.style setPointMarker:[self getPointMarkerWithSize:5 colorCode:0xFFFF1919]];
    
    [surface.renderableSeries add:lineSeries1];
    [surface.renderableSeries add:lineSeries2];
    [surface.renderableSeries add:lineSeries3];
    
    [surface invalidateElement];
}

-(instancetype)initWithFrame:(CGRect)frame{
    self = [super initWithFrame:frame];
    
    if (self) {
        SCIChartSurface * view = [[SCIChartSurface alloc]init];
        surface = view;
        
        [surface setTranslatesAutoresizingMaskIntoConstraints:NO];
        
        [self addSubview:surface];
        NSDictionary *layout = @{@"SciChart":surface};
        
        [self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"|-(0)-[SciChart]-(0)-|" options:0 metrics:0 views:layout]];
        [self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-(0)-[SciChart]-(0)-|" options:0 metrics:0 views:layout]];
        [self initializeSurfaceData];
    }
    
    return self;
}

-(void) initializeSurfaceData {
    
    
    [self createBandRenderableSeries];
    
    id<SCIAxis2DProtocol> axis = [[SCILogarithmicNumericAxis alloc] init];
    [axis setGrowBy: [[SCIDoubleRange alloc]initWithMin:SCIGeneric(0.1) Max:SCIGeneric(0.1)]];
    [surface.xAxes add:axis];
    
    id<SCIAxis2DProtocol> yAxis = [[SCILogarithmicNumericAxis alloc] init];
    [yAxis setGrowBy: [[SCIDoubleRange alloc]initWithMin:SCIGeneric(0.1) Max:SCIGeneric(0.1)]];
    [surface.yAxes add:yAxis];
    
    [surface invalidateElement];
}

-(SCIEllipsePointMarker*) getPointMarkerWithSize: (int)size
                                       colorCode: (uint)colorCode{
    SCIEllipsePointMarker *ellipseMarker = [SCIEllipsePointMarker new];
    [ellipseMarker setWidth:size];
    [ellipseMarker setHeight:size];
    [ellipseMarker setStrokeStyle:[[SCISolidPenStyle alloc]initWithColorCode:colorCode withThickness:0.0]];
    [ellipseMarker setFillStyle:[[SCISolidBrushStyle alloc]initWithColorCode:colorCode]];
    
    return ellipseMarker;
}

@end

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