private void InitializeCharts()
{
var activityGroupsByType = UserActivities.GroupBy(a => a.Type);
Dictionary <string, int> activityTypesWithCount = activityGroupsByType.ToDictionary(group => group.Key.ToString(), group => group.Count());
Dictionary <string, float> activityTypesWithDistances = activityGroupsByType.ToDictionary(group => group.Key.ToString(), group => group.Sum(a => a.Distance));
Dictionary <string, float> activityTypesWithDuration = activityGroupsByType.ToDictionary(group => group.Key.ToString(), group => group.Sum(a => a.MovingTime));
_distanceChartConfig = ChartService.DrawPieChart("Overall distance by type", new SortedDictionary <string, float>(activityTypesWithDistances));
_countChartConfig = ChartService.DrawPieChart("Activity count by type", new SortedDictionary <string, int>(activityTypesWithCount));
_durationChartConfig = ChartService.DrawPieChart("Overall duration by type", new SortedDictionary <string, float>(activityTypesWithDuration));
}