在coreplot iOS的同一Y轴上绘制负值和正值

Question

This is the I am creating scatterplot:

  -(void)createScatterPlotsWithIdentifier:(NSString *)identifier color:(CPTColor *)color forGraph:(CPTGraph *)graph forXYPlotSpace:(CPTXYPlotSpace *)plotSpace{


CPTScatterPlot *scatterPlot = [[CPTScatterPlot alloc] init];
scatterPlot.dataSource = self;
scatterPlot.identifier = identifier;

//Plot a graph with in the plotspace
[plotSpace scaleToFitPlots:[NSArray arrayWithObjects:scatterPlot, nil]];

plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromUnsignedInteger(0) length:CPTDecimalFromUnsignedInteger(30)];
plotSpace.yRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromUnsignedInteger(-50) length:CPTDecimalFromUnsignedInteger(250)];

CPTMutablePlotRange *xRange = [[self getCoreplotSpace].xRange mutableCopy];
[xRange expandRangeByFactor:CPTDecimalFromCGFloat(-1)];
[self getCoreplotSpace].xRange = xRange;

CPTMutableLineStyle *scatterLineStyle = [scatterPlot.dataLineStyle mutableCopy];
scatterLineStyle.lineWidth = 1;
scatterLineStyle.lineColor = color;
scatterPlot.dataLineStyle = scatterLineStyle;

CPTMutableLineStyle *scatterSymbolLineStyle = [CPTMutableLineStyle lineStyle];
scatterSymbolLineStyle.lineColor = color;

CPTPlotSymbol *scatterSymbol = [CPTPlotSymbol ellipsePlotSymbol];
scatterSymbol.fill = [CPTFill fillWithColor:color];
scatterSymbol.lineStyle = scatterSymbolLineStyle;
scatterSymbol.size = CGSizeMake(2.0f, 2.0f);
scatterPlot.plotSymbol = scatterSymbol;

[graph addPlot:scatterPlot toPlotSpace:plotSpace];

}

Configuring the Y-axis like this:

  NSMutableSet *yLabels = [NSMutableSet setWithCapacity:4];
NSMutableSet *yLocations = [NSMutableSet setWithCapacity:4];
NSArray *yAxisLabels = [NSArray arrayWithObjects:@"-50", @"33", @"117", @"200", nil];
NSArray *customTickLocations = [NSArray arrayWithObjects:[NSDecimalNumber numberWithUnsignedInt:-50], [NSDecimalNumber numberWithInt:33], [NSDecimalNumber numberWithInt:117], [NSDecimalNumber numberWithInt:200],nil];

for ( NSUInteger i = 0; i < [yAxisLabels count]; i++ ) {

    NSLog(@"%@",[yAxisLabels objectAtIndex:i]);
    CPTAxisLabel *label = [[CPTAxisLabel alloc] initWithText:[NSString stringWithFormat:@"%@",[yAxisLabels objectAtIndex:i]]  textStyle:axisTextStyle];
    label.tickLocation = CPTDecimalFromInteger([[customTickLocations objectAtIndex:i] integerValue]);

    label.offset = y.majorTickLength;
    if (label) {
        [yLabels addObject:label];
        [yLocations addObject:[NSString stringWithFormat:@"%d",[[customTickLocations objectAtIndex:i] integerValue]]];
    }
    label = nil;
}
y.axisLabels = yLabels;
y.majorTickLocations = [NSSet setWithArray:customTickLocations];

Could you please find the screenshot. I have following issues.

1. I am able to set the y axis but the graph is taking -50 as 0.
2. In screenshot, y axis is not aligned properly.
3. only axis are in bold color. how can I change that to normal.

could you please help me on these issues.

Thanks ...

Thanks

Answer 1

NSString has an integerValue method that will parse the string contents into an NSInteger . Use the doubleValue method for floating point values. For more complex number parsing tasks, use NSScanner .

For example,

label.tickLocation = CPTDecimalFromInteger(yAxisLabels[i].integerValue);

and

[yLocations addObject:@(yAxisLabels[i].integerValue)];