tag:blogger.com,1999:blog-11295132.post112655666912795280..comments2024-02-24T01:46:31.188-08:00Comments on A Neighborhood of Infinity: Adjointssigfpehttp://www.blogger.com/profile/08096190433222340957noreply@blogger.comBlogger1125tag:blogger.com,1999:blog-11295132.post-1128901168715792522005-10-09T16:39:00.000-07:002005-10-09T16:39:00.000-07:00This is just reverse mode AD. But I've never seen ...This is just reverse mode AD. But I've never seen anyone else factor reverse mode AD as the product of two program transformations: forward AD followed by the adjoint. The adjoint step on its own is useful for applications besides differentiating.<BR/><BR/>My description of loops is correct, as you say, for fixed loops. For iterate-until-fixed-point, the implementations I have seen simply 'record' the forward pass and 'replay' it backwards with the same number of iterations on the reverse pass (eg. by building a tree that represents the unrolled loop during the forward run). So I don't see that my description is off. However, it seems to me that you're talking about something more interesting than this simple minded approach. Maybe you have a reference. If you don't post back here I might have to email you...sigfpehttps://www.blogger.com/profile/08096190433222340957noreply@blogger.com