How do I get rid of these magic numbers in my rotation affine transform?
I have a view that is 320x460 (standard iPhone screen) that I want to draw as if it were in landscape mode, though the phone is not oriented that way.  This seems like a simple task, which I tried to solve by creating a subview of size 460x320, and then rotating it 90 degrees through setting the view transformation.  This worked, except that the rotated view was not centered correctly.  To 'fix' this I added a translation transformation, which ended up looking like this:

	CGAffineTransform rotate = CGAffineTransformMakeRotation(M_PI / 2.0);
	[landscapeView setTransform: CGAffineTransformTranslate(rotate, 70.0, 70.0)];

I don't mind having some adjustment transformation, but I have no clue where the magic number 70 came in.  I just played around with it until the edges matched up correctly.  How can I get rid of them, either by eliminating the translation transformation, or by deriving the number from some meaningful math related to the height and width?  
How do I get rid of these magic numbers in my rotation affine transform?
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I have a view that is 320x460 (standard iPhone screen) that I want to draw as if it were in landscape mode, though the phone is not oriented that way.  This seems like a simple task, which I tried to solve by creating a subview of size 460x320, and then rotating it 90 degrees through setting the view transformation.  This worked, except that the rotated view was not centered correctly.  To 'fix' this I added a translation transformation, which ended up looking like this:

	CGAffineTransform rotate = CGAffineTransformMakeRotation(M_PI / 2.0);
	[landscapeView setTransform: CGAffineTransformTranslate(rotate, 70.0, 70.0)];

I don't mind having some adjustment transformation, but I have no clue where the magic number 70 came in.  I just played around with it until the edges matched up correctly.  How can I get rid of them, either by eliminating the translation transformation, or by deriving the number from some meaningful math related to the height and width?  