remove negative axes from coreplot(scatter plot) in iphone

Question

How to remove negative axes from corePlot(scatterplot) in iphone and how to set the area of graph that is visible?

Answer 1

Here are some examples pulled from the CPTTestApp example included with Core Plot:

1. Setting plot ranges:

   CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *)graph.defaultPlotSpace;
   plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromDouble(0.0)
                                                   length:CPTDecimalFromDouble(-10.0)];
   plotSpace.yRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromDouble(0.5)
                                                   length:CPTDecimalFromDouble(1500.0)];
   

   Remember that plot ranges are similar to NSRange—they have a starting location and length. The length can be negative if you want the reverse the direction of an axis.

2. Limiting the length of axes:

   yAxis.visibleRange   = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromInteger(2)
                                                       length:CPTDecimalFromInteger(3)];
   yAxis.gridLinesRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromInteger(2)
                                                       length:CPTDecimalFromInteger(3)];
   

3. Changing the visible area:

   graph.paddingLeft = 60.0;
   graph.paddingTop = 60.0;
   graph.paddingRight = 60.0;
   graph.paddingBottom = 60.0;    
   

   You can also set padding on graph.plotAreaFrame to inset the plot area to create room for axis labels and titles.

Eric

Answer 2

Use plotRangeWithLocation: length: methods.

-(void)initXYAxesRanges{

    //Set graph ranges for x and y planes
    CPXYPlotSpace *plotSpace = (CPXYPlotSpace *)graph.defaultPlotSpace;
    plotSpace.xRange = [CPPlotRange plotRangeWithLocation:CPDecimalFromFloat(0)
                                                   length:CPDecimalFromFloat(10];
    plotSpace.yRange = [CPPlotRange plotRangeWithLocation:CPDecimalFromFloat(0)
                                                   length:CPDecimalFromFloat(10)];
}