CorePlot x axis positioning issue

Question

In the following code I try to add 5 custom labels and display it towards the x axis. But I face following issues. I used the scatter plot sample code to test this. Attaching the image with results as well.!

1. Not all 5 labels are showing.
2. X axis markers start in the minus side. All x should resides in plus side.
3. In x axis I want to get the same effect as y axis. Same grey effect.

// Create graph from theme
graph = [[CPTXYGraph alloc] initWithFrame:CGRectZero];
CPTTheme *theme = [CPTTheme themeNamed:kCPTDarkGradientTheme];
[graph applyTheme:theme];
CPTGraphHostingView *hostingView = (CPTGraphHostingView *)self.view;
hostingView.collapsesLayers = NO; // Setting to YES reduces GPU memory usage, but can slow drawing/scrolling
hostingView.hostedGraph     = graph;

graph.paddingLeft   = 10.0;
graph.paddingTop    = 10.0;
graph.paddingRight  = 10.0;
graph.paddingBottom = 10.0;

// Setup plot space
CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *)graph.defaultPlotSpace;
plotSpace.allowsUserInteraction = YES;
plotSpace.yRange                = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(-80.0) length:CPTDecimalFromFloat(500.0)];
plotSpace.xRange                = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(-1) length:CPTDecimalFromFloat(15.0)];

CPTMutableLineStyle *xLineStyle = [CPTMutableLineStyle lineStyle];
xLineStyle.miterLimit       = 1.0f;
xLineStyle.lineWidth            = 3.0f;
xLineStyle.lineColor = [CPTColor whiteColor];
// Axes
CPTXYAxisSet *axisSet = (CPTXYAxisSet *)graph.axisSet;
CPTXYAxis *x          = axisSet.xAxis;
x.visibleRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(0) length:CPTDecimalFromFloat(100)];
x.axisLineStyle               = xLineStyle;
x.majorTickLineStyle          = xLineStyle;
x.minorTickLineStyle          = xLineStyle;
x.majorIntervalLength         = CPTDecimalFromString(@"1");
x.orthogonalCoordinateDecimal = CPTDecimalFromString(@"1");
x.titleLocation               = CPTDecimalFromFloat(0.5f);
x.titleOffset                 = 5.0f;

x.labelingPolicy = CPTAxisLabelingPolicyNone;
NSArray *customTickLocations = [NSArray arrayWithObjects:[NSDecimalNumber numberWithInt:1], [NSDecimalNumber numberWithInt:2], [NSDecimalNumber numberWithInt:3], [NSDecimalNumber numberWithInt:4], nil];
NSArray *xAxisLabels         = [NSArray arrayWithObjects:@"Label A", @"Label B", @"Label C", @"Label D", @"Label E", nil];
NSUInteger labelLocation     = 0;
NSMutableArray *customLabels = [NSMutableArray arrayWithCapacity:[xAxisLabels count]];
for ( NSNumber *tickLocation in customTickLocations ) {
    CPTAxisLabel *newLabel = [[CPTAxisLabel alloc] initWithText:[xAxisLabels objectAtIndex:labelLocation++] textStyle:x.labelTextStyle];
    newLabel.tickLocation = [tickLocation decimalValue];
    newLabel.offset       = x.labelOffset + x.majorTickLength;
    newLabel.rotation     = M_PI / 4;
    [customLabels addObject:newLabel];
    [newLabel release];
}

x.axisLabels = [NSSet setWithArray:customLabels];

CPTXYAxis *y = axisSet.yAxis;
y.visibleRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(0) length:CPTDecimalFromFloat(500)];
y.majorIntervalLength         = CPTDecimalFromString(@"40");
y.minorTicksPerInterval       = 5;
y.orthogonalCoordinateDecimal = CPTDecimalFromString(@"2");

y.delegate             = self;

// Create a blue plot area
CPTScatterPlot *boundLinePlot  = [[[CPTScatterPlot alloc] init] autorelease];
CPTMutableLineStyle *lineStyle = [CPTMutableLineStyle lineStyle];
lineStyle.miterLimit        = 1.0f;
lineStyle.lineWidth         = 3.0f;
lineStyle.lineColor         = [CPTColor blueColor];
boundLinePlot.dataLineStyle = lineStyle;
boundLinePlot.identifier    = @"Blue Plot";
boundLinePlot.dataSource    = self;
[graph addPlot:boundLinePlot];

// Do a blue gradient
CPTColor *areaColor1       = [CPTColor colorWithComponentRed:0.3 green:0.3 blue:1.0 alpha:0.8];
CPTGradient *areaGradient1 = [CPTGradient gradientWithBeginningColor:areaColor1 endingColor:[CPTColor clearColor]];
areaGradient1.angle = -90.0f;
CPTFill *areaGradientFill = [CPTFill fillWithGradient:areaGradient1];
boundLinePlot.areaFill      = areaGradientFill;
boundLinePlot.areaBaseValue = [[NSDecimalNumber zero] decimalValue];

// Add plot symbols
CPTMutableLineStyle *symbolLineStyle = [CPTMutableLineStyle lineStyle];
symbolLineStyle.lineColor = [CPTColor blackColor];
CPTPlotSymbol *plotSymbol = [CPTPlotSymbol ellipsePlotSymbol];
plotSymbol.fill          = [CPTFill fillWithColor:[CPTColor blueColor]];
plotSymbol.lineStyle     = symbolLineStyle;
plotSymbol.size          = CGSizeMake(10.0, 10.0);
boundLinePlot.plotSymbol = plotSymbol;

// Add some initial data
NSMutableArray *contentArray = [[NSMutableArray alloc] init];
NSUInteger i;
for ( i = 0; i < 5; i++ ) {

    id x = [NSNumber numberWithFloat:i];
    id y = [NSNumber numberWithFloat:200-i];
    [contentArray addObject:[NSMutableDictionary dictionaryWithObjectsAndKeys:x, @"x", y, @"y", nil]];
}
self.dataForPlot = contentArray;
[contentArray release];

Answer 1

1. You only created four labels. The customTickLocations array contains four locations; one label is created for each location.

2. The labels are at the locations specified in the code. The data points are at (0, 1, 2, 3, 4) while the labels are at (1, 2, 3, 4). The y-axis crosses the x-axis at x=2 because of the orthogonalCoordinateDecimal property setting.

3. Don't set the axis or tick line styles on the x-axis if you want to keep the default ones from the theme.