Question

How to change area gradient color for negative values in Gradient Scatter Plot in Core-Plot in iPhone?

I want gradient colors as below:

• For positive values to be Green

• For negative values to be Red.

How should I do that?

Answer 1

Just implement the following method of the CPBarPlotDataSource is OK:

- (CPFill *)barFillForBarPlot:(CPBarPlot *)barPlot recordIndex:(NSUInteger)index
{
    if (barPlot.identifier == @"profit") {
        id item = [self.profits objectAtIndex:index];
        double profit = [[item objectForKey:@"profit"] doubleValue];

        if (profit < 0.0) {
            return [CPFill fillWithGradient:[CPGradient gradientWithBeginningColor:[CPColor redColor] endingColor:[CPColor blackColor]]];
        }
    }

    return nil;
}

Hope to help:)