Suppose my data looks like this: 2372 Kansas KS2000111 HUMBOLDT, CITY OF ATRAZINE 1.3 05/07/2006 9104 Kansas KS2000111 HUMBOLDT, CITY OF ATRAZINE 0.34 07/23/2006 9212 Kansas KS2000111 HUMBOLDT, CITY OF ATRAZINE 0.33 02/11/2007 2094 Kansas KS2000111 HUMBOLDT, CITY OF ATRAZINE 1.4 05/06/2007 16763 Kansas KS2000111 HUMBOLDT, CITY OF ATRAZINE 0.61 05/11/2009 1076 Kansas KS2000111 HUMBOLDT, CITY OF METOLACHLOR 0.48 05/12/2002 1077 Kansas KS2000111 HUMBOLDT, CITY OF METOLACHLOR 0.3 05/07/2006 I want to be able to subset by the Analyte and a partial match on the date(namely I just want the year). I have been trying this, but I know it isn't quite right. data[data$Analyte=="ATRAZINE" & grep("2006",as.character(data$Date)),] Any suggestions?