r - substract subset of data frame from the same data frame -

i have data frame of following structure: have ana number of rows , columns

v<-c("control", na, 1, 2, 4, "test", na, 1, 2, 4, "test", na, 1, 2, 4, "test", na, 1, 2, 4) df<- as.data.frame(t(matrix(v, nrow=5, ncol=4))) colnames(df)<-c("id", "g1", "g2", "g3", "g4") df        id   g1 g2 g3 g4 1 control <na>  1  2  4 2    test <na>  1  2  4 3    test <na>  1  2  4 4    test <na>  1  2  4 

i subtract rows id==control other rows, giving me following result:

result            id   g1 g2 g3 g4     1    test <na>  0  0  0     2    test <na>  0  0  0     3    test <na>  0  0  0 

i tried sweep() function, tried putting through loops, nothing worked.

it amazing if me. thank you!

assuming there single "control", create logical index based on 'control' value ('i1'), subset 'df' 'id' not 'control' ('df1'), use map subtract columns in 'df1' same columns 'id' 'control' , assign output corresponding columns in 'df1'.

i1 <- df$id=="control" df1 <- df[!i1,] df1[3:5] <- map(`-`, df1[3:5], df[i1,3:5]) df1 #    id   g1 g2 g3 g4 #2 test <na>  0  0  0 #3 test <na>  0  0  0 #4 test <na>  0  0  0 

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or instead of using map can replicate make lengths equal both datasets , subtraction

df1[3:5] <- df1[3:5] - df[i1, 3:5][col(df1[3:5])] 

data

df[-(1:2)] <- lapply(df[-(1:2)], function(x) as.numeric(as.character(x)))