It is possible to pass in a bunch of additional arguments to your function, but these must be the same for each call of your function. Use lapply() twice to call select_el() over all elements in split_low: once with the index equal to 1 and a second time with the index equal to 2. Within the lapply function, we simply need to specify the name of our list (i.e. Assign the result to names and years, respectively. I have a function that has as inputs userX, Time1, Time2, Time3 and return a data frame with 1 observation and 19 variables. Refer to the below table … df.list < - list(df1,df2,) res <- lapply(df.list, function(x) rowMeans(subset(x, select I have multiple data frames and would like to take the same action across an identically named column in each data frame. MARGIN argument is not required here, the specified function is applicable only through columns. The next functions are using lists as input data… Example 2: lapply() Function. The l in front of apply stands for “list”. data.table documentation: Applying a summarizing function to multiple variables Hello guys, I have a list L1 of matrix. my_list) and the function … Using lapply with two lists. In Example 2, I’ll illustrate how to use the lapply function. 2. lapply() function. The trick to using lapply is to recognise that only one item can differ between different function calls.. Defining a function and being explicit about passing the argument in is more flexible than passing the name of a function … multiple - tapply function with two arguments . I thought about using lapply, but if I understand correctly, it only takes lapply() always returns a list, ‘l’ in lapply() refers to ‘list’. I want to apply that function to all the observations of the first data frame to make a new data frame with 2000 observations and 19 variables. Functions and lapply ... You might see this sort of construction where a function is defined but not returned into a variable called an anonymous function. tapply works on a vector, for a data.frame you can use by (which is a wrapper for tapply, take a look at the code): > by (df.1 [, c (3: 5)], df.1 $ state, FUN = colSums) df.1 $ state: AA apples cherries plums 111 222 333-----df.1 $ state: BB apples cherries plums -111-222-333 sapply(x, f, simplify = FALSE, USE.NAMES = FALSE) is the same as lapply(x, f). sum multiple columns by group with tapply (2) . lapply() deals with list and data frames in the input. Apply function to multiple data frames r. Same function over multiple data frames in R, Make a list of data frames then use lapply to apply the function to them all. The Family of Apply functions pertains to the R base package, and is populated with functions to manipulate slices of data from matrices, arrays, lists and data frames in a repetitive way.Apply Function in R are designed to avoid explicit use of loop constructs. The Apply family comprises: apply, lapply , sapply, vapply, mapply, rapply, and tapply. The challenge is to identify the parts of your analysis that stay the same and those that differ for each call of the function. lapply returns a list of the same length as X, each element of which is the result of applying FUN to the corresponding element of X. sapply is a user-friendly version and wrapper of lapply by default returning a vector, matrix or, if simplify = "array", an array if appropriate, by applying simplify2array(). Here are some examples: vars1<-c(5,6,7) vars2<-c(10,20,30) myFun <-function(var1,var2) To apply a function to multiple parameters, you can pass an extra variable while using any apply function.. 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