library(dplyr) library(magrittr) dat2<-read.table(text="Code Y M D Q N O 41003 81 1 19 0.16 7.17 2.5 41003 77 9 22 0.197 6.8 2.2 41003 79 7 28 0.21 4.7 6.2 41005 79 8 17 0.21 5.5 7.2 41005 80 10 30 0.21 6.84 2.6 41005 80 12 20 0.21 6.84 2.4 41005 79 6 14 0.217 5.61 3.55 41009 79 2 21 0.218 5.56 4.04 41009 79 5 27 0.218 6.4 3.12 41009 80 11 29 0.22 6.84 2.8 41009 78 5 28 0.232 6 3.2 41009 81 8 20 0.233 6.39 1.6 41009 79 9 30 0.24 5.6 7.5 41017 79 10 20 0.24 5.3 7.1 41017 80 7 30 0.24 6.73 2.6", header=TRUE) dat3 <- dat2 %>% group_by(Code) %>% mutate( MinByCodeY = min(Y, na.rm = T), ) %>% arrange(Code)
This returns a dataframe with a new variable "MinByCodeY" which is the minimum value in Y for each group of Code where the minimum value within the group is added to each row of data in the original dataframe. Tim -----Original Message----- From: R-help <r-help-boun...@r-project.org> On Behalf Of javad bayat Sent: Wednesday, August 24, 2022 3:45 AM To: R-help@r-project.org Subject: [R] Getting minimum value of a column according a factor column of a dataframe [External Email] Dear all; I am trying to get the minimum value of a column based on a factor column of the same data frame. My data frame is like the below: Code Y M D Q N O 41003 81 1 19 0.16 7.17 2.5 41003 77 9 22 0.197 6.8 2.2 41003 79 7 28 0.21 4.7 6.2 41005 79 8 17 0.21 5.5 7.2 41005 80 10 30 0.21 6.84 2.6 41005 80 12 20 0.21 6.84 2.4 41005 79 6 14 0.217 5.61 3.55 41009 79 2 21 0.218 5.56 4.04 41009 79 5 27 0.218 6.4 3.12 41009 80 11 29 0.22 6.84 2.8 41009 78 5 28 0.232 6 3.2 41009 81 8 20 0.233 6.39 1.6 41009 79 9 30 0.24 5.6 7.5 41017 79 10 20 0.24 5.3 7.1 41017 80 7 30 0.24 6.73 2.6 I want to get the minimum value of the "Q" column with the whole row values, according to the "Code" column which is a factor. Overall it will give me 4 rows, with the value of "Q". Below is a code that I used but it did not give me what I wanted. > x[which(x$Q == min(x$Q)),] Sincerely -- Best Regards Javad Bayat M.Sc. Environment Engineering Alternative Mail: bayat...@yahoo.com [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fstat.ethz.ch%2Fmailman%2Flistinfo%2Fr-help&data=05%7C01%7Ctebert%40ufl.edu%7C9c40fa5f8b354251cf5c08da85e82878%7C0d4da0f84a314d76ace60a62331e1b84%7C0%7C0%7C637969529406639528%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=wRIHPCENQspDLjF9IbGTsyM1kJ5hYhIwfYuFSU9UFDM%3D&reserved=0 PLEASE do read the posting guide https://nam10.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.r-project.org%2Fposting-guide.html&data=05%7C01%7Ctebert%40ufl.edu%7C9c40fa5f8b354251cf5c08da85e82878%7C0d4da0f84a314d76ace60a62331e1b84%7C0%7C0%7C637969529406639528%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=jthiGDRGroo5sh8snIDQHHGsWAndtxp5SCB7HvyhWg8%3D&reserved=0 and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.