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ros / roslisp_common

Clone of the old roslisp_common SVN repo from code.ros.org.
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Added a transform-diff function. #14

Closed mpomarlan closed 9 years ago

mpomarlan commented 9 years ago

For convenience, added a transform-diff function:

(defun transform-diff (transform-To transform-From)

This seems like a very common task when working with transforms, so it makes sense to have it in the core package, unless something like it is here already.

airballking commented 9 years ago

@mpomarlan Could you please also export the function in the lisp package.lisp?

airballking commented 9 years ago

@mpomarlan Is this still on your list or should I close the pull request?

mpomarlan commented 9 years ago

On the order of multiplication: as defined in the comment ("the transform that, when left-multiplied, will convert transform-From into transform-To"), it should be fine. If transform-Diff is the result, then this means: transform-To = transform-Diff * transform-From (aka, transform-To * inverse(transform-From) = transform-Diff).

On package.lisp exporting: done.

Cheers!

airballking commented 9 years ago

@mpomarlan I rechecked your comment and the code. They are indeed consistent. I do not see a use for this but you probably have one. So, I'll merge it in. ;)