I'm tryng to use loess normalization function based on externals controls (like MSP) as in Yang et al.; 2002 paper. I work with bioconductor marrayNorm package. I identified my controls in the maControls structure of marrayLayout as a vector of 0 and 1. Is someone still use it ? for the moment I just have ... test <- maNormMain(manip.raw, f.loc = list(maNormLoess(x="maA", y="maM", z="maControls",subset=TRUE))) but answer is Error in simpleLoess(y, x, w, span, degree, parametric, drop.square, normalize, : invalid `x' [[alternative HTML version deleted]]