[R] apply function to multiple list arguments

[Rui Barradas]

Hello,

Have you tried

mapply(f, list_df, list_par, MoreArgs = list(z = fix), SIMPLIFY = FALSE)

?


Hope this helps,

Rui Barradas

Em 14-10-2014 19:42, Carlos Nasher escreveu:
> Hi R helpers,
>
> I'm struggling how to apply a function to multiple lists. My function uses
> a dataframe, a list of parameters and a fixed value as arguments. Now I
> want to apply that function to several dataframes contained in list, with
> several lists of parameters (also contained in a list) and the fixed value.
> Here's an example:
>
>
> #####
>
> fix <- 2 # fixed value
>
> x <- c(1,2,3)
> y <- c(4,5,6)
>
> df_1 <- data.frame(x,y) # first dataframe
> df_2 <- 2*df_1 # second dataframe
>
> list_df <- list(df_1,df_2) # list containing dataframes
>
> par_1 <- list(a=5,b=10) # first list of parameters
> par_2 <- list(a=6,b=11) # second list of parameters
>
> list_par <- list(par_1,par_2) # list of lists of parameters
>
> f <- function(data,params,z){
>    res <- (data$x*params$a+data$y*params$b)*z
>    return(res)
> }
>
> res_1 <- f(data = df_1, params = par_1, z = fix) # result of applying
> function to first dataframe and first list of parameters
> res_2 <- f(data = df_2, params = par_2, z = fix) # result of applying
> function to second dataframe and second list of parameters
>
> #####
>
> I got the list of dataframes and parameters from a former use of lapply. I
> was hoping to get the desired results (res_1, res_2) again in a list. I
> tried mapply, but I don't get it running. Can anybody help?
>
> Thanks and best regards,
> Carlos
>
>
>