Hi Sam, I'd take the similar tack of removing the < instead. Note that if you import the data frame using the stringsAsFactors=FALSE argument, you don't need the first step.
metals$Cedar.Creek <- as.character(metals$Cedar.Creek) metals$Cedar.Creek <- gsub("<", "", metals$Cedar.Creek) metals$Cedar.Creek <- as.numeric(metals$Cedar.Creek) R> str(metals) 'data.frame': 19 obs. of 2 variables: $ Parameter : Factor w/ 20 levels "Antimony","Arsenic",..: 1 2 3 4 6 7 8 9 10 11 ... $ Cedar.Creek: num 100 100 500 100 10 1000 100 516 550 10 ... Sarah On Wed, Jul 9, 2014 at 1:19 PM, Sam Albers <tonightstheni...@gmail.com> wrote: > Hello, > > I have recently received a dataset from a metal analysis company. The > dataset is filled with less than symbols. What I am looking for is a > efficient way to subset for any whole numbers from the dataset. The column > is automatically formatted as a factor because of the "<" symbols making it > difficult to deal with the numbers is a useful way. > > So in sum any ideas on how I could subset the example below for only whole > numbers? > > Thanks in advance! > > Sam > > #code > > metals <- > > > structure(list(Parameter = structure(c(1L, 2L, 3L, 4L, 6L, 7L, > 8L, 9L, 10L, 11L, 12L, 13L, 15L, 16L, 17L, 18L, 19L, 20L, 1L), .Label > = c("Antimony", > "Arsenic", "Barium", "Beryllium", "Boron (Hot Water Soluble)", > "Cadmium", "Chromium", "Cobalt", "Copper", "Lead", "Mercury", > "Molybdenum", "Nickel", "pH 1:2", "Selenium", "Silver", "Thallium", > "Tin", "Vanadium", "Zinc"), class = "factor"), Cedar.Creek = structure(c(3L, > 3L, 7L, 3L, 2L, 4L, 3L, 34L, 36L, 2L, 5L, 7L, 3L, 7L, 3L, 45L, > 4L, 4L, 3L), .Label = c("<1", "<10", "<100", "<1000", "<200", > "<5", "<500", "0.1", "0.13", "0.5", "0.8", "1.07", "1.1", "1.4", > "1.5", "137", "154", "163", "165", "169", "178", "2.3", "2.4", > "22", "24", "244", "27.2", "274", "3", "3.1", "40.2", "43", "50", > "516", "53.3", "550", "569", "65", "66.1", "68", "7.6", "72", > "77", "89", "951"), class = "factor")), .Names = c("Parameter", > "Cedar.Creek"), row.names = c(NA, 19L), class = "data.frame") > -- Sarah Goslee http://www.functionaldiversity.org ______________________________________________ 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.