iOS Coreplot多个Y轴

Question

i have been searching for this question for an answer for 3 days but could not figure it out.

i need to add 3 scatterplots to a graph and here's my code :

CPTXYAxis *x = [[CPTXYAxis alloc] init];
CPTXYAxis *lefty = [[CPTXYAxis alloc] init];
CPTXYAxis *righty = [[CPTXYAxis alloc] init];

x.coordinate = CPTCoordinateX;
lefty.coordinate = CPTCoordinateY;
righty.coordinate = CPTCoordinateY;

CPTAxisSet *axisSetTmp = [[CPTAxisSet alloc] init];

for initializations and creating 3 differend plotspaces like :

float xAxisMin = 0;
float xAxisMax = 350;
float yAxisMin = 0;
float yAxisMax = 50;

// We modify the graph's plot space to setup the axis' min / max values.
CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *)self.graph.defaultPlotSpace;
plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(xAxisMin) length:CPTDecimalFromFloat(xAxisMax - xAxisMin)];
plotSpace.yRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(yAxisMin) length:CPTDecimalFromFloat(yAxisMax - yAxisMin)];
x.plotSpace = plotSpace;

and finally creating my plot like :

CPTScatterPlot *plot = [[CPTScatterPlot alloc] init];
plot.dataSource = self;
plot.identifier = @"mainplot";
plot.dataLineStyle = lineStyle;
plot.plotSymbol = nil;
plot.plotSpace = plotSpace;

and when i run this , 3 lines are added but i got only 1 y-axis. could not figure out the problem.

any help will be appreciated.

Answer 1

1. Did you add the new axes to the graph?

    graph.axisSet.axes = [NSArray arrayWithObjects:x, lefty, righty, nil]; 

2. If all of the axes and plots will have the same plot ranges, you can use the same plot space for all of them. A new graph starts with one you can use ( defaultPlotSpace ). Use the -addPlotSpace: method to add additional plot spaces to the graph.