Hi, Pyne, I agree with you that it is good to have an inverse function. Thanks for your suggestion and tips. We will try to implement it next week. Thanks, Chao-Jen spyne at broadinstitute.org wrote: > > Hi, > > The reason I need the inverse function for logicle is because > after I have computationally identified the cluster of events in > logicle-transformed marker space, now I want to use the knowledge > of that range of events in the original, untransformed scale for > sorting out similar events in the subsequent experiments. > > My guess is that this may not be a very far-fetched scenario, > and since the transformation is deterministic and bijective > anyway, an inverse function would be good to have, at least for > the default argument settings. One option is of course a slow > numerical computation method. > > However, since the transformation is monotonic, for a fixed setting > of arguments (e.g. the default setting), doing a simple binary search > over a reasonable range is a cheap way to approximate the inverse > within a desirable accuracy. > > Thanks! > -Pyne > > > Quoting Chao-Jen Wong <cwon2 at="" fhcrc.org="">: > >> Hi, Pyne >> >> That is an interesting question. flowCore does not have an inverse >> function for the logicle transformation. Since the logicle >> transformation is an one-to-one and onto function, it is possible to >> implement an inverse function. It is, however, not straightforward. Do >> you really really need such a function? >> >> spyne at broadinstitute.org wrote: >>> >>> Hi, >>> >>> I applied logicle transformation (with default arguments) >>> to my data points, then detected the subpopulations of >>> interest in the transformed data, and now I want to >>> revert the subpopulations back to the original scale of >>> the untransformed state. >>> >>> In other words, if I want to apply the inverse of the logicle >>> transformtion (applied with default arguments, which I do not >>> know) to my data, is that possible? >>> >>> Thanks. >>> -Pyne >>> >>> _______________________________________________ >>> Bioconductor mailing list >>> Bioconductor at stat.math.ethz.ch >>> https://stat.ethz.ch/mailman/listinfo/bioconductor >>> Search the archives: >>> http://news.gmane.org/gmane.science.biology.informatics.conductor >> >> >> -- >> Chao-Jen Wong >> Program in Computational Biology >> Division of Public Health Sciences >> Fred Hutchinson Cancer Research Center >> 1100 Fairview Avenue N., M2-B876 >> PO Box 19024 >> Seattle, WA 98109 >> 206.667.4485 >> cwon2 at fhcrc.org >> >> > > -- Chao-Jen Wong Program in Computational Biology Division of Public Health Sciences Fred Hutchinson Cancer Research Center 1100 Fairview Avenue N., M2-B876 PO Box 19024 Seattle, WA 98109 206.667.4485 cwon2 at fhcrc.org