Question

I’ve got an array of points for a standard line-graph like so:

Array = [NSArray arrayWithObjects: 
               [NSArray arrayWithObjects: [NSNumber numberWithInt: 10], [NSNumber numberWithInt: 20], nil],
               [NSArray arrayWithObjects: [NSNumber numberWithInt: 30], [NSNumber numberWithInt: 40], nil],
               nil];

The points show up on the graph display fine, but I’m having trouble finding out how to connect these two points to form a line. All the examples I can find online deal with plotting the paths of functions, such as f(x)=1/x. I’m simply interested in connecting two points to display a line.

Thank you.

---

EDIT 1

Here is how I set up the graph:

graph = [[CPTXYGraph alloc] init];
    CPTTheme *theme = [CPTTheme themeNamed:kCPTStocksTheme];
    [graph applyTheme:theme];
    graph.frame = self.view.bounds;
    graph.paddingRight = 4.0f;
    graph.paddingLeft = 4.0f;
    graph.plotAreaFrame.masksToBorder = NO;
    graph.plotAreaFrame.cornerRadius = 0.0f;
    CPTMutableLineStyle *borderLineStyle = [CPTMutableLineStyle lineStyle];
    borderLineStyle.lineColor = [CPTColor whiteColor];
    borderLineStyle.lineWidth = 0.01f;
    graph.plotAreaFrame.borderLineStyle = borderLineStyle;
    self.graphHost.hostedGraph = graph;

---

EDIT 2

To anyone with a similar problem, the solution you are looking for is the dataLineStyle property.

Answer 1

If we’re talking about directly drawing lines in Quartz, something like this…

// get current context
CGContextRef ct = UIGraphicsGetCurrentContext();

CGContextBeginPath(ct);
CGContextMoveToPoint(ct, startPointX, startPointY);
CGContextAddLineToPoint(ct, endPointX, endPointY);
CGContextStrokePath(ct);

Without more info, I can’t really help.