Dear R users Are any R users aware of implementations of Semi-Definite optimization in R. For example, has anybody implemented any of the numerous public domain C libraries for SDP in R and would they be willing to share. My objective here is to implement variants of "Maximum Variance Unfolding" as outlined in, for example, http://www.icml2006.org/icml_documents/camera-ready/131_A_Duality_View_of_Sp.pdf Any ideas would be warmly appreciated. Simon Gatehouse School of Biological Earth & Environmental Sciences University of New South Wales