Peak Data Insertion Problems-Please Try Lowering ppm Param August 24, 2012, 01:03:30 PM Hello,When I process my XCMS data for metaXCMS on the R platform I receive this message during feature detection "Peak Data Insertion Problems-Please Try Lowering ppm parameter". While the process completes and I can move on to the next step, I am wondering what this means and if there is a way I can lower the ppm parameter that is currently set at 25 ppm.Thank you,Stacy Quote Selected
Re: Peak Data Insertion Problems-Please Try Lowering ppm Par Reply #1 – August 30, 2012, 02:35:46 AM Hi Stacy,the centWave algorithm has a two step feature detection framework.The first step is the detection of connected centroids, which are called ROI (region of interest).If within one scan the selection of a centroid is not distinct, this could be caused by a too large search window (ppm parameter).If you have not many warnings, you can safely ignore them. If not, then you should lower your ppm parameter.Carsten Quote Selected