Re: [R] apply fn to many dataframes

2009-05-25 Thread Wacek Kusnierczyk
jim holtman wrote: > You have to return a value from the function in the lapply and assign the > result to another object: > > >> df <- data.frame(a=1,b=2,c=3,d=4) >> a <- list(df,df,df,df) >> # to change the name of the second, you have to change the name and then >> > return > >> # the

Re: [R] apply fn to many dataframes

2009-05-25 Thread markleeds
Hi:Â you have to return the dataframe inside the lapply. I also changed = to <- but I doubt that matters. d1 <- data.frame(x1=1,x3=4) d2 <- data.frame(x1=2,x3=5) d3 <- data.frame(x1=3,x3=6) d4 <- data.frame(x1=4,x3=7) a = list(d1,d2,d3,d4) print(a) lapply(a,function(.df

Re: [R] apply fn to many dataframes

2009-05-25 Thread jim holtman
You have to return a value from the function in the lapply and assign the result to another object: > df <- data.frame(a=1,b=2,c=3,d=4) > a <- list(df,df,df,df) > # to change the name of the second, you have to change the name and then return > # the dataframe as the return value and assign it bac

[R] apply fn to many dataframes

2009-05-25 Thread James Fearon
Hi, Say I have dataframes d1, d2, ... , dn, and I want to apply a function to all of them. For example, say I want to change the name of the second variable in each dataframe to "x2". The following doesn't work: a = list(d1,d2,d3,d4) lapply(a,function(x) names(x)[2] = "x2") What would work