Thank you Peter. I am really new to this. The spreadsheet I am working with has 12,379 rows with the first row consisting of the variable names and 12,378 rows of data. There are seven columns, and the 7th column is the only one with numerical data ("Results").
I need to match up the variable Results with the variable "Anlysis_Soil", which is the type of test performed by the labs on one of 20 different soil samples. Here are some examples of the Anlysis_Soil variable: Anlysis_Soil Bases-Aluminum KCL Extr-2008-116 Bases-Aluminum KCL Extr-2008-116 Bases-Aluminum KCL Extr-2008-117 Bases-Aluminum KCL Extr-2008-118 Bases-Aluminum KCL Extr-2008-118 Bases-Aluminum KCL Extr-2008-119 Bases-Aluminum KCL Extr-2008-120 Bases-Aluminum KCL Extr-2008-120 Bases-Aluminum KCL Extr-2009-101 Actually, I am not interested in any of the above, because there are too few (less than 9). I think I need to first identify the unique Anlysis_Soil from the entire list, and I thought using "list" might work: > anlyses <- list(Anlysis_Soil) > str(anlyses) List of 1 $ : Factor w/ 1695 levels "Bases-Aluminum KCL Extr-2008-116",..: 1 1 2 3 3 4 5 5 6 6 ... > It does correctly identify there are 1695 unique "Anlysis_Soil" variables. However, "anlyses" contains all 12,378 "Anlysis_Soil" variables. For example: print(anlyses) ... ... ... [12374] Soil pH & EC-Soil EC (1to2)-2009-115 [12375] Soil pH & EC-Soil EC (1to2)-2009-115 [12376] Soil pH & EC-Soil EC (1to2)-2009-115 [12377] Soil pH & EC-Soil EC (1to2)-2009-115 [12378] Soil pH & EC-Soil EC (1to2)-2009-115 1695 Levels: Bases-Aluminum KCL Extr-2008-116 ... And once again shows correctly that there are 1,695 unique "Anlysis_Soil" variables. Once the unique Anlysis_Soil variables are identified, I need to determine the ones greater than 8, and I see how that could be done with your code. I am not clear what you mean by, "for (myV in myVars)" ? Is myV the name of one of the unique variables that has at least 9 Results? Is myVars the entire column of "Anlysis_Soil" ? I am not sure if this is any clearer. Thanks, Jerry Floren Minnesota Department of Agriculture -- View this message in context: http://n4.nabble.com/Help-with-subset-tp1049883p1058242.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.