2016-04-22 149 views
2

我的任務是創建頻率表與統計摘要。我的目標是創建一個可以簡單導出爲ex​​cel的數據框。 其中大部分可以使用存儲過程在SQL中,但我決定在R中執行此操作。我正在學習R,所以我可能會做很長的路要走。這是問題的一個後續從getting-r-frequency-counts-for-all-possible-answers一個簡單的方法來實現頻率計數與平均值,總和,長度和SD在R

鑑於

Id <- c(1,2,3,4,5,6,7,8,9,10) 
    ClassA <- c(1,NA,3,1,1,2,1,4,5,3) 
    ClassB <- c(2,1,1,3,3,2,1,1,3,3) 
    R <- c(1,2,3,NA,9,2,4,5,6,7) 
    S <- c(3,7,NA,9,5,8,7,NA,7,6) 
    df <- data.frame(Id,ClassA,ClassB,R,S) 

    ZeroTenNAScale <- c(0:10,NA); 

    R.freq <- setNames(nm=c('answer','value'),data.frame(table(factor(df$R,levels=ZeroTenNAScale,exclude=NULL)))); 
    R.freq[, 1] <- as.numeric(as.character(R.freq[, 1])) 
    R.freq <- cbind(question='R',R.freq) 

    S.freq <- setNames(nm=c('answer','value'),data.frame(table(factor(df$S,levels=ZeroTenNAScale,exclude=NULL)))); 
    S.freq[, 1] <- as.numeric(as.character(S.freq[, 1])) 
    S.freq <- cbind(question='S',S.freq) 

    R.mean = mean(df$R, na.rm = TRUE) 
    R.length = sum(!is.na(df$R)) 
    R.sd = sd(df$R, na.rm = TRUE) 
    R.sum = sum(df$R, na.rm = TRUE) 

    S.mean = mean(df$S, na.rm = TRUE) 
    S.length = sum(!is.na(df$S)) 
    S.sd = sd(df$S, na.rm = TRUE) 
    S.sum = sum(df$S, na.rm = TRUE) 

    S.row <- cbind('S','sum',as.numeric(S.sum)) 
    S.row <- setNames(nm=c('question','answer','value'),data.frame(S.row)) 
    S.freq = rbind(S.freq, S.row) 

    S.row <- cbind('S','length',as.numeric(S.length)) 
    S.row <- setNames(nm=c('question','answer','value'),data.frame(S.row)) 
    S.freq = rbind(S.freq, S.row) 

    S.row <- cbind('S','mean',as.numeric(S.mean)) 
    S.row <- setNames(nm=c('question','answer','value'),data.frame(S.row)) 
    S.freq = rbind(S.freq, S.row) 

    S.row <- cbind('S','sd',as.numeric(S.sd)) 
    S.row <- setNames(nm=c('question','answer','value'),data.frame(S.row)) 
    S.freq = rbind(S.freq, S.row) 

    R.row <- cbind('R','sum',as.numeric(R.sum)) 
    R.row <- setNames(nm=c('question','answer','value'),data.frame(R.row)) 
    R.freq = rbind(R.freq, R.row) 

    R.row <- cbind('R','length',as.numeric(R.length)) 
    R.row <- setNames(nm=c('question','answer','value'),data.frame(R.row)) 
    R.freq = rbind(R.freq, R.row) 

    R.row <- cbind('R','mean',as.numeric(R.mean)) 
    R.row <- setNames(nm=c('question','answer','value'),data.frame(R.row)) 
    R.freq = rbind(R.freq, R.row) 

    R.row <- cbind('R','sd',as.numeric(R.sd)) 
    R.row <- setNames(nm=c('question','answer','value'),data.frame(R.row)) 
    R.freq = rbind(R.freq, R.row) 

    result <- rbind(R.freq,S.freq) 
    result <- cbind(filter='None',result) 
    result 

我得到

filter question answer   value 
1 None  R  0    0 
2 None  R  1    1 
3 None  R  2    2 
4 None  R  3    1 
5 None  R  4    1 
6 None  R  5    1 
7 None  R  6    1 
8 None  R  7    1 
9 None  R  8    0 
10 None  R  9    1 
11 None  R  10    0 
12 None  R <NA>    1 
13 None  R sum    39 
14 None  R length    9 
15 None  R mean 4.33333333333333 
16 None  R  sd 2.64575131106459 
17 None  S  0    0 
18 None  S  1    0 
19 None  S  2    0 
20 None  S  3    1 
21 None  S  4    0 
22 None  S  5    1 
23 None  S  6    1 
24 None  S  7    3 
25 None  S  8    1 
26 None  S  9    1 
27 None  S  10    0 
28 None  S <NA>    2 
29 None  S sum    52 
30 None  S length    8 
31 None  S mean    6.5 
32 None  S  sd 1.8516401995451 

這是差不多就是我要找的。下一步,我看到它開始在一些函數中包裝,以簡化代碼,然後再開始添加類ClassA = 1,ClassA = n + 1 ... ClassA = NA,ClassB = 1,ClassB = 2 ... ClassB = NA。有沒有更簡單的方法來做到這一點?

Ernest AImo研究答案後新代碼是

# https://stackoverflow.com/questions/36790376/a-simpler-way-to-achieve-a-frequency-count-with-mean-sum-length-and-sd-in-r/36794422#36794422 

    # create the summary function 
    summaryStatistics <- function(x) { 
     xx <- na.omit(x) 
     c(table(factor(x, levels=0:10), useNA='always', exclude=NULL), 
      sum=sum(xx), length=length(x), mean=mean(xx), sd=sqrt(var(xx))) 
    } 

    # create the test data frame 
    Id <- c(1,2,3,4,5,6,7,8,9,10) 
    ClassA <- c(1,NA,3,1,1,2,1,4,5,3) 
    ClassB <- c(2,1,1,3,3,2,1,1,3,3) 
    R <- c(1,2,3,NA,9,2,4,5,6,7) 
    S <- c(3,7,NA,9,5,8,7,NA,7,6) 
    df <- data.frame(Id,ClassA,ClassB,R,S) 

    # create the result 
    result <- setNames(
     nm=c('answer','question','value'), 
     as.data.frame(
      as.table(
       simplify2array(
        lapply(
         df[c('R', 'S')], 
         summaryStatistics 
        ) 
       ) 
      ) 
     ) 
    ) 

    # change the order to question, answer, value 
    result <- result[, c(2, 1, 3)] 

    # add the filter 
    result <- cbind(filter='None',result) 

    # return the result 
    result 

這是更簡單,讓我的訓練我們的隊伍更加簡單等任務。感謝Ernest AImo

關於我的R理解接下來的問題是Using vectors in R to change the output of a function

回答

2

是,它絕對可以簡化。通常你會使用匯總函數如

smry <- function(x, levels) { 
    xx <- na.omit(x) 
    c(table(factor(x, levels=levels), useNA='always', exclude=NULL), 
     sum=sum(xx), length=length(x), mean=mean(xx), sd=sqrt(var(xx))) 
} 

然後將它應用到數據

> lapply(df[c('R', 'S')], smry, 0:10) 
$R 
     0   1   2   3   4   5   6   7 
0.000000 1.000000 2.000000 1.000000 1.000000 1.000000 1.000000 1.000000 
     8   9  10  <NA>  sum length  mean  sd 
0.000000 1.000000 0.000000 1.000000 39.000000 10.000000 4.333333 2.645751 

$S 
     0  1  2  3  4  5  6  7 
0.00000 0.00000 0.00000 1.00000 0.00000 1.00000 1.00000 3.00000 
     8  9  10  <NA>  sum length  mean  sd 
1.00000 1.00000 0.00000 2.00000 52.00000 10.00000 6.50000 1.85164 

的不同子集。如果你非得把一切都放在一個數據幀

> as.data.frame(as.table(simplify2array(lapply(df[c('R', 'S')], smry, 0:10)))) 
    Var1 Var2  Freq 
1  0 R 0.000000 
2  1 R 1.000000 
3  2 R 2.000000 
4  3 R 1.000000 
5  4 R 1.000000 
6  5 R 1.000000 
7  6 R 1.000000 
8  7 R 1.000000 
9  8 R 0.000000 
10  9 R 1.000000 
11  10 R 0.000000 
12 <NA> R 1.000000 
13 sum R 39.000000 
14 length R 10.000000 
15 mean R 4.333333 
16  sd R 2.645751 
17  0 S 0.000000 
18  1 S 0.000000 
19  2 S 0.000000 
20  3 S 1.000000 
21  4 S 0.000000 
22  5 S 1.000000 
23  6 S 1.000000 
24  7 S 3.000000 
25  8 S 1.000000 
26  9 S 1.000000 
27  10 S 0.000000 
28 <NA> S 2.000000 
29 sum S 52.000000 
30 length S 10.000000 
31 mean S 6.500000 
32  sd S 1.851640 

然後只需根據需要更改列名稱/添加列。

+0

可以將水平傳遞給函數。我有一些問題有不同的尺度。例如,一些問題的等級= 1:3。 –

+0

謝謝@ErnestA。乾杯。 –

4

一兩件事你可以做,以減少你的代碼大小包裹彙總統計的功能:

myStats <- function(x) { 
    answer <- c("sum"=sum(x, na.rm = TRUE), "length"=sum(!is.na(x)), 
       "mean"=mean(x, na.rm = TRUE), "sd"=sd(x, na.rm = TRUE)) 

    return(answer) 
} 

這將返回一個按照您在輸出中的順序排列彙總統計的命名向量。然後,您可以rbind返回的值以及名稱到您的頻率表:

R.stats <- myStats(df$R) 
rbind(R.freq, data.frame("question"='R', "answer"=names(R.stats), 
         "value"=R.stats))