PowerPlotPercolation logo

US bank failures

This is a bar chart with the number of failed banks in the US from 2000 to 2010. I got the idea from Ray Wenderlich's tutorials on the iPhone.

This page describes the class “FailedBanks” in the PowerPlot demo app.

Failed banks in the US

Creating this chart is very simple with a factory method. However, since the x-axis shows years the default format is not optimal since it has a separator – the year “2000” would be displayed as “2,000” which looks bad for dates. Therefore, we have to manually generate new tick labels with an appropriate NSNumberFormatter.

    // Create and configure a bar chart.
    WSChart *barChart = [WSChart barPlotWithFrame:[self.view bounds]
                                             data:[DemoData failedBanks]
                                            style:kChartBarPlain
                                      colorScheme:kColorWhite];
    WSPlotAxis *axis = [barChart firstPlotAxis];
    NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];
    [formatter setNumberStyle:NSNumberFormatterDecimalStyle];
    [formatter setGroupingSeparator:@""];
    [[axis ticksX] setTickLabelsWithFormatter:formatter];
    [formatter release];
    [barChart setChartTitle:NSLocalizedString(@"Failed banks by year", @"")];

The numbers of bank failures are provided by the DemoData class. The chart also has a title which is set by the chartTitle property.