如何從函數返回結果和書面聲明？

Question

我想這個函數返回結果（數字）和文本。

sum_of_squares_cubes <- function(x,y) { 
    sq = x^2 + y^2 
    cube = x^3 + y^3 
    return(list(sq, cube)) 
    cat("The sum of squares is", sq, "\n" , 
     "The sum of cubes is", cube, "\n" , 
    ) 
} 

這樣做只會返回結果的編號。

所需的輸出：

sum_of_squares_cubes(2,3) 
13 
35 
"The sum of squares is 13" 
"The sum of cubes is 35" 

Answer 1

修改函數來做到這一點呢？

sum_of_squares_cubes <- function(x,y) { 
    sq = x^2 + y^2 
    cube = x^3 + y^3 
    text <- paste("The sum of squares is ", sq, "\n", 
       "The sum of cubes is ", cube, "\n", sep = '') 
    return(list(sq, cube, text)) 
} 

Answer 2

這可能是因爲這些人有同樣的困惑因爲這樣做你，你會很樂意與他們的意見，但實際上回不同類的多個項目（這是你問）你做需要一個單個列表（可能是複雜的結構）。

sum_of_squares_cubes <- function(x,y) { 
    sq = x^2 + y^2 
    cube = x^3 + y^3 
    return(list(sq, cube, sqmsg=paste("The sum of squares is", sq, "\n") , 
         cubemsg= paste("The sum of cubes is", cube, "\n") 
     )) 
    } 

> sum_of_squares_cubes(2,4) 
[[1]] 
[1] 20 

[[2]] 
[1] 72 

$sqmsg 
[1] "The sum of squares is 20 \n" 

$cubemsg 
[1] "The sum of cubes is 72 \n" 

Answer 3

這裏是sprintf的一個簡單的解決方案：

sum_of_squares_cubes <- function(x,y) { 
    sq = x^2 + y^2 
    cube = x^3 + y^3 
    text1 <- sprintf("The sum of squares is %d", sq) 
    text2 <- sprintf("and the sum of cubes is %d", cube) 
    return(cat(c("\n", sq, "\n", cube, "\n", text1, "\n", text2))) 
} 

，結果是這樣的：

13 
35 
The sum of squares is 13 
and the sum of cubes is 35