slds-lmu / lecture_optimization

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Typo in def of L-smoothness #2

Open chriskolb opened 1 year ago

chriskolb commented 1 year ago

The "Deep dive on GD and optimality" video just popped up on my youtube feed and I think the definition of L-smoothness contains a typo. Instead of

|| \nabla \fx - \nabla f(\tilde{\xv}) || \le L ||\fx - f(\tilde{\xv}) || \quad \text{ for all } \xv, \tilde{\xv}

I think it should be

|| \nabla \fx - \nabla f(\tilde{\xv}) || \le L ||\xv - \tilde{\xv} || \quad \text{ for all } \xv, \tilde{\xv}

https://github.com/slds-lmu/lecture_optimization/blob/67a1b17e01f0a2376061e7da9d678481d656be0f/slides/04-multivariate-first-order/slides-multivar-first-order-3-gd-deepdive-optimality.tex#L49

(source e.g. here https://www.stat.cmu.edu/~ryantibs/convexopt-F13/scribes/lec6.pdf)