r - Replicate values of column along rows -

given following data frame:

df1 <- data.table( v1=c(0,0,0,0),v2=c(0,0,0,0),v3=c(0,2,0,2)) df1    v1 v2 v3 1:  0  0  0 2:  0  0  2 3:  0  0  0 4:  0  0  2 

i seek replicate values of v3 along entire row, that:

df2    v1 v2 v3 1:  0  0  0 2:  2  2  2 3:  0  0  0 4:  2  2  2 

how can achieve this?

many in advance.

you use base-r syntax:

# overwrite df1[] <- df1$v3   # make new table df2   <- copy(df1) df2[] <- df1$v3  

i think data.table-ish way modify many columns set:

# overwrite (j in setdiff(names(df1),"v3")) set(df1, j = j, value = df1$v3)  # make new table -- simple extension 

finally, there several other ideas @akrun, @davidarenburg , @veerendragadekar:

# overwrite df1[, (1:ncol(df1)) := v3] # david/veerendra  # make new table df2 <- setdt(rep(list(df1$v3), ncol(df1))) # akrun df2 <- df1[, rep("v3",ncol(df1)), = false] # david