Another mathematical equation... Upper and Lower Bounds

[iSDK]

Hi,

Here is another mathematical code snippet on how to get the upper and lower bounds of a number

.h

- (int)getUpperBoundForNumber:(int)number roundedTo:(int)roundedto;
- (int)getLowerBoundForNumber:(int)number roundedTo:(int)roundedto;

.m

- (int)getUpperBoundForNumber:(int)number roundedTo:(int)roundedto {
	return number + (roundedto/2);
}

- (int)getLowerBoundForNumber:(int)number roundedTo:(int)roundedto {
	return number - (roundedto/2);
}

To call it

int lowerboundof200roundedtothenearest100 = [self getLowerBoundForNumber:200 roundedTo:100];
int upperboundof200roundedtothenearest100 = [self getUpperBoundForNumber:200 roundedTo:100];

NSLog(@"%i", [self getLowerBoundForNumber:200 roundedTo:100]);
NSLog(@"%i", [self getUpperBoundForNumber:200 roundedTo:100]);

[smasher]

Have you tested this code? In integers 200 - 100/2 is 150.

[iSDK]

Oops. Its fixed.

Originally Posted by smasher

Have you tested this code? In integers 200 + 100/2 is 150.

[smasher]

Can you explain what this code is used for? I guess I don't understand what the "lower bound of a number" is.

-(void) test{
	int lowerboundof200roundedtothenearest100 = [self getLowerBoundForNumber:200 roundedTo:100];
	int upperboundof200roundedtothenearest100 = [self getUpperBoundForNumber:200 roundedTo:100];
		
	int lowerboundof199roundedtothenearest25 = [self getLowerBoundForNumber:199 roundedTo:25];
	int upperboundof199roundedtothenearest25 = [self getUpperBoundForNumber:199 roundedTo:25];
		
	NSLog(@"%i", lowerboundof200roundedtothenearest100);
	NSLog(@"%i", upperboundof200roundedtothenearest100);
	NSLog(@"%i", lowerboundof199roundedtothenearest25);
	NSLog(@"%i", upperboundof199roundedtothenearest25);
}

2011-02-20 08:30:03.809 testProj2[86942:207] 150
2011-02-20 08:30:04.078 testProj2[86942:207] 250
2011-02-20 08:30:04.303 testProj2[86942:207] 187
2011-02-20 08:30:04.538 testProj2[86942:207] 211

[MiniRobinho]

Originally Posted by smasher

Can you explain what this code is used for? I guess I don't understand what the "lower bound of a number" is.

-(void) test{
	int lowerboundof200roundedtothenearest100 = [self getLowerBoundForNumber:200 roundedTo:100];
	int upperboundof200roundedtothenearest100 = [self getUpperBoundForNumber:200 roundedTo:100];
		
	int lowerboundof199roundedtothenearest25 = [self getLowerBoundForNumber:199 roundedTo:25];
	int upperboundof199roundedtothenearest25 = [self getUpperBoundForNumber:199 roundedTo:25];
		
	NSLog(@"%i", lowerboundof200roundedtothenearest100);
	NSLog(@"%i", upperboundof200roundedtothenearest100);
	NSLog(@"%i", lowerboundof199roundedtothenearest25);
	NSLog(@"%i", upperboundof199roundedtothenearest25);
}

2011-02-20 08:30:03.809 testProj2[86942:207] 150
2011-02-20 08:30:04.078 testProj2[86942:207] 250
2011-02-20 08:30:04.303 testProj2[86942:207] 187
2011-02-20 08:30:04.538 testProj2[86942:207] 211

Your example of 199 rounded to 25 doesn't make sense - if the number was rounded to the nearest 25 then it couldn't have been 199 could it? Say you have a ruler that has 1 cm graduations. Then when you measure something you would say that its 45 cm rounded to the nearest 1 cm. That means the actual value of the item you measured could be between 45 + (1/2) and 45 - (1/2) which is 44.5 and 45.5 cm. The above methods are just showing what these two upper/lower bounds are.

[smasher]

Originally Posted by MiniRobinho

Your example of 199 rounded to 25 doesn't make sense - if the number was rounded to the nearest 25 then it couldn't have been 199 could it?

Say you have a ruler that has 1 cm graduations. Then when you measure something you would say that its 45 cm rounded to the nearest 1 cm. That means the actual value of the item you measured could be between 45 + (1/2) and 45 - (1/2) which is 44.5 and 45.5 cm. The above methods are just showing what these two upper/lower bounds are.

I considered that explanation of the function's purpose -- it gives you the upper and lower bounds of the range that rounds to the given number -- but it doesn't do that either. 150 and 250 can't both round to 200.

I've also never had a need to get the limits for the range that rounds to a particular number, so I'm curious what it's used for.

[iisword]

yeah, this isn't useful from what I can tell

[iSDK]

I don't particularly care whether you think this is useful or not to you. To some other people this may be. I have spent some time creating an algorithm and this thread to help other people out that may actually find this helpful. So having you disrespecting me after I have spent some of my free time to help out others is totally unacceptable.

Originally Posted by iisword

yeah, this isn't useful from what I can tell

[Rhade]

Originally Posted by iisword

yeah, this isn't useful from what I can tell

Neither was your bump.

Originally Posted by iSDK

I don't particularly care whether you think this is useful or not to you. To some other people this may be. I have spent some time creating an algorithm and this thread to help other people out that may actually find this helpful. So having you disrespecting me after I have spent some of my free time to help out others is totally unacceptable.

Grow a pair. This was hardly worth being reported.