core plot how to draw two line and use different data - ios

Question

I created a core plot graph, have one x-axis, two y-axis, now, I want to have two lines and first use the first y-axis, second use the second y-axis, but it doesn't work. Who can guide me?
- (void)viewDidLoad
{
[super viewDidLoad];
graph = [[CPTXYGraph alloc] initWithFrame:CGRectMake(10, 100, 300, 300)];
// graph.backgroundColor = [CPTColor clearColor].cgColor;
CPTTheme * theme = [CPTTheme themeNamed:kCPTPlainWhiteTheme];
[graph applyTheme:theme];
CPTGraphHostingView * hostingView = [[CPTGraphHostingView alloc] initWithFrame:CGRectMake(10, 100, 300, 300)];
hostingView.hostedGraph = graph;
[self.view addSubview:hostingView];
[hostingView release];
graph.fill = [CPTFill fillWithColor:[CPTColor clearColor]];
// Plot area
// graph.plotAreaFrame.fill = [CPTFill fillWithColor:[CPTColor clearColor]];
graph.plotAreaFrame.paddingTop = 10;
graph.plotAreaFrame.paddingBottom = 50;
graph.plotAreaFrame.paddingLeft = 20.0;
graph.plotAreaFrame.paddingRight = 20.0;
graph.plotAreaFrame.cornerRadius = 10.0;
graph.plotAreaFrame.masksToBorder = NO;
// graph.plotAreaFrame.axisSet.borderLineStyle = [CPTLineStyle lineStyle];
graph.plotAreaFrame.plotArea.fill = [CPTFill fillWithColor:[CPTColor clearColor]];
// Setup plot space
CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *)graph.defaultPlotSpace;
plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromDouble(1) length:CPTDecimalFromDouble(7)];
plotSpace.yRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromDouble(53.0) length:CPTDecimalFromDouble(4)];
// Line styles
CPTMutableLineStyle *axisLineStyle = [CPTMutableLineStyle lineStyle];
axisLineStyle.lineWidth = 3.0;
axisLineStyle.lineCap = kCGLineCapRound;
// Label x axis with a fixed interval policy
CPTXYAxisSet *axisSet = (CPTXYAxisSet *)graph.axisSet;
CPTXYAxis *x = axisSet.xAxis;
x.separateLayers = YES;//
x.orthogonalCoordinateDecimal = CPTDecimalFromDouble(53);
x.majorIntervalLength = CPTDecimalFromDouble(1);
x.minorTicksPerInterval = 1;
x.tickDirection = CPTSignNegative;
x.axisLineStyle = axisLineStyle;
x.majorTickLength = 2.0;
x.majorTickLineStyle = axisLineStyle;
// Label y with an automatic labeling policy.
axisLineStyle.lineColor = [CPTColor greenColor];
CPTXYAxis *y = axisSet.yAxis;
y.labelingPolicy = CPTAxisLabelingPolicyAutomatic;
y.separateLayers = YES;//
y.minorTicksPerInterval = 0;
y.tickDirection = CPTSignNegative;
y.orthogonalCoordinateDecimal = CPTDecimalFromDouble(1.0);
y.axisLineStyle = axisLineStyle;
y.majorTickLength = 6.0;
y.majorTickLineStyle = axisLineStyle;
// Label y2 with an equal division labeling policy.
axisLineStyle.lineColor = [CPTColor orangeColor];
CPTXYPlotSpace * plotSpace2 = [[CPTXYPlotSpace alloc] init];
plotSpace2.xRange = plotSpace.xRange;
plotSpace2.yRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(1) length:CPTDecimalFromFloat(5)];
[graph addPlotSpace:plotSpace2];
CPTXYAxis *y2 = [[[CPTXYAxis alloc] init] autorelease];
y2.coordinate = CPTCoordinateY;
y2.plotSpace = plotSpace2;
y2.orthogonalCoordinateDecimal = CPTDecimalFromDouble(8.0);
y2.labelingPolicy = CPTAxisLabelingPolicyAutomatic;//
y2.separateLayers = NO;
y2.preferredNumberOfMajorTicks = 0;
y2.minorTicksPerInterval = 0;
y2.tickDirection = CPTSignPositive;
y2.axisLineStyle = axisLineStyle;
y2.majorTickLength = 6.0;
y2.majorTickLineStyle = axisLineStyle;
y2.minorTickLength = 4.0;
y2.titleOffset = 30.0;
//
CPTMutableLineStyle * lineStyle1 = [[CPTMutableLineStyle lineStyle] retain];
lineStyle1.lineWidth = 3.0f;
lineStyle1.lineColor = [CPTColor blueColor];
dataSourceLinePlot1 = [[CPTScatterPlot alloc] init];
dataSourceLinePlot1.identifier = #"1plot";
CPTPlotSymbol *plotSymbol1 = [CPTPlotSymbol ellipsePlotSymbol];
plotSymbol1.size = CGSizeMake(10, 10);
plotSymbol1.fill = [CPTFill fillWithColor:[CPTColor redColor]];
plotSymbol1.lineStyle = lineStyle1;
CPTMutableShadow *shadow1 = [CPTMutableShadow shadow];
shadow1.shadowColor = [CPTColor blueColor];
shadow1.shadowBlurRadius = 10.0;
dataSourceLinePlot1.shadow = shadow1;
dataSourceLinePlot1.plotSymbol = plotSymbol1;
dataSourceLinePlot1.dataLineStyle = lineStyle1;
dataSourceLinePlot1.dataSource = self;
[graph addPlot:dataSourceLinePlot1];
//-----------------------------------
CPTMutableLineStyle * lineStyle2 = [[CPTMutableLineStyle lineStyle] retain];
lineStyle2.lineWidth = 3.0f;
lineStyle2.lineColor = [CPTColor greenColor];
dataSourceLinePlot2 = [[CPTScatterPlot alloc] init];
dataSourceLinePlot2.identifier = #"2plot";
CPTPlotSymbol * plotSymbol2 = [CPTPlotSymbol ellipsePlotSymbol];
plotSymbol2.size = CGSizeMake(10, 10);
plotSymbol2.fill = [CPTFill fillWithColor:[CPTColor redColor]];
plotSymbol2.lineStyle = lineStyle2;
CPTMutableShadow *shadow2 = [CPTMutableShadow shadow];
shadow2.shadowColor = [CPTColor greenColor];
shadow2.shadowBlurRadius = 10.0;
dataSourceLinePlot2.shadow = shadow2;
dataSourceLinePlot2.plotSymbol = plotSymbol2;
dataSourceLinePlot2.dataLineStyle = lineStyle2;
dataSourceLinePlot2.dataSource = self;
[graph addPlot:dataSourceLinePlot2];
// Add the y2 axis to the axis set
graph.axisSet.axes = [NSArray arrayWithObjects:x, y, y2, nil];
dataArray1 = [[NSMutableArray alloc] init];
dataArray2 = [[NSMutableArray alloc] init];
for(int i=0; i< 7; i++){
float a = (float)(random()%40 + 530) / 10;
[dataArray1 addObject:[NSNumber numberWithFloat:a]];
}
for (int i = 0; i < 7; i++) {
// float a = (float)(random()%40 + 530) / 10;
[dataArray2 addObject:[NSNumber numberWithFloat:4]];
}
NSLog(#"array1 = %#,array2 = %#",dataArray1,dataArray2);
}
there is my delegate:
-(NSUInteger)numberOfRecordsForPlot:(CPTPlot *)plot
{
NSLog(#"%d",[dataArray1 count]);
if ([[plot identifier] isEqual:#"1plot"]) {
return [dataArray1 count];
}
return [dataArray2 count];
}
- (NSNumber *) numberForPlot:(CPTPlot *)plot field:(NSUInteger)fieldEnum recordIndex:(NSUInteger)index {
if(fieldEnum == CPTScatterPlotFieldY){
if ([[plot identifier] isEqual:#"1plot"]) {
return [dataArray1 objectAtIndex:index];
}else{
return [dataArray2 objectAtIndex:index];
}
}else{
return [NSNumber numberWithFloat:index];
}
}

Answer 1

You are setting the datasource delegate to self before the arrays have any data put into them. You need to either initialize the array earlier or call [graph reloadData];