CGGeometryクラスの位置やサイズ操作系の関数紹介 ref: http://qiita.com/hachinobu/items/f8ac32870739c7d4eab8

サンプル

    UIView *view1 = [[UIView alloc] initWithFrame:CGRectMake(40, 50, 180, 180)];
    view1.backgroundColor = [UIColor redColor];
    [self.view addSubview:view1];
    UIView *view2 = [[UIView alloc] initWithFrame:CGRectMake(70, 90, 180, 200)];
    view2.backgroundColor = [UIColor yellowColor];
    [self.view addSubview:view2];
    CGRect unionRect = CGRectUnion(view1.frame, view2.frame);
    NSLog(@"unionRect:%@", NSStringFromCGRect(unionRect));
    UIView *unionView = [[UIView alloc] initWithFrame:unionRect];
    unionView.backgroundColor = [UIColor clearColor];
    unionView.layer.borderColor = [[UIColor blackColor] CGColor];
    unionView.layer.borderWidth = 1.0;
    [self.view addSubview:unionView];

サンプル(CGRectMaxXEdge)

    CGFloat amount = 50.0f;
    CGRect rect = self.view.frame;
    CGRect sliceRect = CGRectNull;
    CGRect remainderRect = CGRectNull;
    CGRectDivide(rect, &sliceRect, &remainderRect, amount, CGRectMaxXEdge);
    NSLog(@"rect:%@", NSStringFromCGRect(rect)); //rect:{{0, 0}, {320, 568}}
    NSLog(@"sliceRect:%@", NSStringFromCGRect(sliceRect)); //sliceRect:{{270, 0}, {50, 568}}
    NSLog(@"remainderRect:%@", NSStringFromCGRect(remainderRect)); //remainderRect:{{0, 0}, {270, 568}}
    UIView *sliceView = [[UIView alloc] initWithFrame:sliceRect];
    sliceView.backgroundColor = [UIColor redColor];
    [self.view addSubview:sliceView];
    UIView *remainderView = [[UIView alloc] initWithFrame:remainderRect];
    remainderView.backgroundColor = [UIColor blueColor];
    [self.view addSubview:remainderView];

サンプル(CGRectMaxYEdge)

    CGFloat amount = 50.0f;
    CGRect rect = self.view.frame;
    CGRect sliceRect = CGRectNull;
    CGRect remainderRect = CGRectNull;
    CGRectDivide(rect, &sliceRect, &remainderRect, amount, CGRectMaxYEdge);
    NSLog(@"rect:%@", NSStringFromCGRect(rect)); //rect:{{0, 0}, {320, 568}}
    NSLog(@"sliceRect:%@", NSStringFromCGRect(sliceRect)); //sliceRect:{{0, 518}, {320, 50}}
    NSLog(@"remainderRect:%@", NSStringFromCGRect(remainderRect)); //remainderRect:{{0, 0}, {320, 518}}
    UIView *sliceView = [[UIView alloc] initWithFrame:sliceRect];
    sliceView.backgroundColor = [UIColor redColor];
    [self.view addSubview:sliceView];
    UIView *remainderView = [[UIView alloc] initWithFrame:remainderRect];
    remainderView.backgroundColor = [UIColor blueColor];
    [self.view addSubview:remainderView];

サンプル(CGRectMinXEdge)

    CGFloat amount = 50.0f;
    CGRect rect = self.view.frame;
    CGRect sliceRect = CGRectNull;
    CGRect remainderRect = CGRectNull;
    CGRectDivide(rect, &sliceRect, &remainderRect, amount, CGRectMinXEdge);
    NSLog(@"rect:%@", NSStringFromCGRect(rect)); //rect:{{0, 0}, {320, 568}}
    NSLog(@"sliceRect:%@", NSStringFromCGRect(sliceRect)); //sliceRect:{{0, 0}, {50, 568}}
    NSLog(@"remainderRect:%@", NSStringFromCGRect(remainderRect)); //remainderRect:{{50, 0}, {270, 568}}
    UIView *sliceView = [[UIView alloc] initWithFrame:sliceRect];
    sliceView.backgroundColor = [UIColor redColor];
    [self.view addSubview:sliceView];
    UIView *remainderView = [[UIView alloc] initWithFrame:remainderRect];
    remainderView.backgroundColor = [UIColor blueColor];
    [self.view addSubview:remainderView];

サンプル(CGRectMinYEdge)

    CGFloat amount = 50.0f;
    CGRect rect = self.view.frame;
    CGRect sliceRect = CGRectNull;
    CGRect remainderRect = CGRectNull;
    CGRectDivide(rect, &sliceRect, &remainderRect, amount, CGRectMinYEdge);
    NSLog(@"rect:%@", NSStringFromCGRect(rect)); //rect:{{0, 0}, {320, 568}}
    NSLog(@"sliceRect:%@", NSStringFromCGRect(sliceRect)); //sliceRect:{{0, 518}, {320, 50}}
    NSLog(@"remainderRect:%@", NSStringFromCGRect(remainderRect)); //remainderRect:{{0, 0}, {320, 518}}
    UIView *sliceView = [[UIView alloc] initWithFrame:sliceRect];
    sliceView.backgroundColor = [UIColor redColor];
    [self.view addSubview:sliceView];
    UIView *remainderView = [[UIView alloc] initWithFrame:remainderRect];
    remainderView.backgroundColor = [UIColor blueColor];
    [self.view addSubview:remainderView];

結果

    standardizeRect:{{-100, -50}, {100, 50}}