Question

May i know how to round up a NSNumber in object C ?

for(int i=6; i>=0; i--) 
{
    DayOfDrinks *drinksOnDay = [appDelegate.drinksOnDayArray objectAtIndex:i];

    NSString * dayString= [NSDate stringForDisplayFromDateForChart:drinksOnDay.dateConsumed];

    [dayArray addObject:dayString];//X label for graph the day of drink.

    drinksOnDay.isDetailViewHydrated = NO;

    [drinksOnDay hydrateDetailViewData];

    NSNumber *sdNumber =  drinksOnDay.standardDrinks;
    [sdArray addObject: sdNumber];      
}

inside this sdArray are all the numbers like this 2.1, 1.3, 4.7, 3.1, 4.8, 15.1, 7.2;

i need to plot a graph Y axis so i need a string of whatever is from the NSNumber to show
a NSString of this {@”0″, @”2″, @”4″, @”6″, @”8″, @”10″, @”12″,@”14″,@”16″}. as i need to start from zero, i need to determine which is the biggest number value. in this case it will be 15.1 to show 16 in the graph. instead of doing a static labeling, i will like to do a dynamic labeling.

what you have seen in the graph is static numbering not dynamic.

i’m sorry for missing out the important info.

thanks for all the comments

Answer 1

Your edit now makes a lot more sense. Here is an example of getting all even numbers from your 0 to your max value in your NSArray of NSNumbers (assuming all values are positive, could be changed to support negative values by finding minimum float value as well).

NSArray *sdArray = [NSArray arrayWithObjects:
                    [NSNumber numberWithFloat:2.1],
                    [NSNumber numberWithFloat:1.3],
                    [NSNumber numberWithFloat:4.7],
                    [NSNumber numberWithFloat:3.1],
                    [NSNumber numberWithFloat:4.8],
                    [NSNumber numberWithFloat:15.1],
                    [NSNumber numberWithFloat:7.2],
                    nil];

//Get max value using KVC
float fmax = [[sdArray valueForKeyPath:@"@max.floatValue"] floatValue];

//Ceiling the max value
int imax = (int)ceilf(fmax);

//Odd check to make even by checking right most bit
imax = (imax & 0x1) ? imax + 1 : imax;

NSMutableArray *array = [NSMutableArray arrayWithCapacity:(imax / 2) + 1];
//Assuming all numbers are positive 
//(should probably just use unsigned int for imax and i)
for(int i = 0; i <= imax; i +=2)
{
    [array addObject:[NSString stringWithFormat:@"%d", i]];
}

NSLog(@"%@", array);