Folks, I need to create matched test and / control pairs from a (dis)similarity matrix. I am not sure if the existing matching softwares (e.g., optmatch, matchit ) will allow me to input my own dissimilarity matrix. It seems that these algorithms are focusing more on observational studies with the distance measure being operationalized by the probability of belonging to the existing test and control cells. I would appreciate any help here. I guess I could otherwise simply look up the dissimilarity matrix to select pairs. That kind of gets cumbersome if you have 65 by 65 matrix. Thx. Raghu [[alternative HTML version deleted]]