如何应用“复杂”用户定义的函数在一个tibble的每个元素上 [英] How to apply a "complicated" user defined function on each element of a tibble

问题描述

我对这个（看似简单的）问题的答案进行了高低调查，但是空洞了，所以我希望有人能够帮助我或者指引我朝着正确的方向前进。

我有一个相当复杂的子模型，我想要应用于数据集，但是如果我只是使用use mutate，我会得到一个错误变量必须是长度为1或21。添加rowwise（）似乎不会影响它。

让我用下面这个愚蠢的例子来说明这个问题： （x = 10：20，y = c（a，b，a，b）， b，a，b，a，b，a，b，a））

staticData < - tibble（x = 0 ：100，y = c（a），f = x / 100）％>联合（tibble（x = 0：100，y = c（b），f = x / 1000））

ComplicatedFunction< - 函数（mystaticData，myx，myy）{
＃创建基表
myBaseTable< - tibble（
y = myy，
x = c（myx：（myx + 20））
）
#add f rates
myBaseTable< - left_join（myBaseTable，mystaticData）
#add stuff
myBaseTable< ; - myBaseTable％>％
mutate（z = 1 - （f * 0.8））％>％
mutate（zCumulative = cumprod（z））
#Calculate the thing
myCalculatedThi ng< - sum（myBaseTable $ zCumulative）

return（myCalculatedThing）
}

＃这是我想要做的事
myData％> ;％mutate（newcol = ComplicatedFunction（mystaticData = staticData，
myx = x，
myy = y））
#this works
ComplicatedFunction（mystaticData = staticData，
myx = 19，
myy =b）
ComplicatedFunction（mystaticData = staticData，
myx = 20，
myy =a）

#This工程（但将是愚蠢的，因为我想为每行评估函数）
myData％>％mutate（newcol = ComplicatedFunction（mystaticData = staticData，
myx = 15，
myy =a））

＃这不再有效，但我不明白我在做什么错误
myData％>％ mutate（newcol = ComplicatedFunction（mystaticData = staticData，
myx = x，
myy =a））

＃我尝试了rowwise（），但这似乎不起作用
myData％>％rowwise（）％>％mutate（newcol = ComplicatedFunction（mystaticData = staticData，
myx = x，
myy = y））

我希望有人能向我解释我在这里做错了什么。

Sylvain

解决方案

您可以通过使用 partial 创建一个新函数来实现它：

  library（purrr ）
 newCF<  -  partial（ComplicatedFunction，mystaticData = staticData）
 myData％>％rowwise（）％>％mutate（newcol = newCF（myx = x，
 my y = y））
  

I have searched high and low for the answer to this (seemingly simple) problem, but came up empty so I hope someone can help me or point me in the right direction.

I have a fairly complicated submodel that I want to apply to a dataset, but if I just use use mutate I get an error Variables must be length 1 or 21. adding rowwise() doesnt seem to impact it.

Let me use the following silly illustration of the problem:

myData <- tibble(x=10:20, y=c("a", "b","a", "b","a", "b","a", "b","a", "b","a"))

staticData <- tibble(x=0:100, y=c("a"),f=x/100) %>% union (tibble(x=0:100, y=c("b"),f=x/1000))

ComplicatedFunction <- function(mystaticData, myx, myy) {
  #make the base table 
  myBaseTable <- tibble(
    y = myy,
    x = c(myx:(myx + 20)) 
  )
  #add  f rates
  myBaseTable <- left_join(myBaseTable,mystaticData)
  #add stuff
  myBaseTable <- myBaseTable %>% 
    mutate(z = 1 - (f * 0.8)) %>% 
    mutate(zCumulative = cumprod(z)) 
  #Calculate the thing
  myCalculatedThing <- sum(myBaseTable$zCumulative)

  return(myCalculatedThing)
}

#This is what I want to do 
myData %>% mutate(newcol = ComplicatedFunction(mystaticData = staticData, 
                                               myx = x, 
                                               myy = y))
#this works
ComplicatedFunction(mystaticData = staticData, 
                    myx = 19, 
                    myy = "b")
ComplicatedFunction(mystaticData = staticData, 
                    myx = 20, 
                    myy = "a")

#This works (but would be silly as I want the function to be evaluated for each line)
myData %>% mutate(newcol = ComplicatedFunction(mystaticData = staticData, 
                                               myx = 15, 
                                               myy = "a"))

#This no longer works, but I dont understand what I am doing wrong
myData %>% mutate(newcol = ComplicatedFunction(mystaticData = staticData, 
                                               myx = x, 
                                               myy = "a"))

#I tried rowwise(), but this doesnt seem to work either 
myData %>% rowwise() %>% mutate(newcol = ComplicatedFunction(mystaticData = staticData, 
                                               myx = x, 
                                               myy = y))

I hope someone can explain to me what I am doing wrong here.

Many thanks in advance!

Sylvain

解决方案

You can do it by creating a new function using partial:

library(purrr)
newCF <- partial(ComplicatedFunction, mystaticData = staticData)
myData %>% rowwise() %>% mutate(newcol = newCF(myx = x, 
                                           myy = y))

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