Hello, I want to hightligh spots (with different "controls" status) on MA plots. Here is a print screen of the control section of my mArrayRaw object Control spots: There are 5 types of controls : Blank Empty na OK RNC 960 225 334 21521 192 As you can see there is 5 differents levels of control spot (Blank, Empty, na, OK and RNC). For highliting ONE specific category of control spots it's working well : # example with For N/A spots na.spots <- maText(subset=maControls(christian.raw[,1]) == "na", col="Red", labels="O") maPlot(christian.raw[,1], text.func = na.spots, legend.func = NULL, lines.func = NULL) To highlight spots of multiple control status (for example "NA" OR "Empty") I've tried this R code: na.empty.spots <- maText(subset=(maControls(christian.raw[,1]) == "na" || "Empty"), col="Red", labels="O") maPlot(christian.raw[,1], text.func = na.empty.spots, legend.func = NULL, lines.func = NULL) Result: Error in maControls(christian.raw[, 1]) == "na" || "Empty" : invalid `y' type in `x || y' I tried too ("na" || "Empty" ------> "na || Empty") : na.empty.spots <- maText(subset=(maControls(christian.raw[,1]) == "na || Empty"), col="Red", labels="O") maPlot(christian.raw[,1], text.func = na.empty.spots, legend.func = NULL, lines.func = NULL) I get a MA plot without any hightlighed spots. Does anybody know how to handle this problem? Regards, Francis