轉置數據幀變量並在[r]中添加空值，唯一的計數

Question

我正在嘗試構建如下的數據幀（如DataProfile）的彙總表。 這個想法是將每一列轉換成一行，併爲count，nulls，not nulls，unique添加變量，並添加這些變量的額外變量。

看起來應該有更好的方法來做到這一點。有沒有這樣的功能？

#trying to write the functions within dplyr & magrittr framework 
library(tidyverse) 

mtcars[2,2] <- NA # Add a null to test completeness 

# 
total <- mtcars %>% summarise_all(funs(n())) %>% melt 
nulls <- mtcars %>% summarise_all(funs(sum(is.na(.)))) %>% melt 
filled <- mtcars %>% summarise_all(funs(sum(!is.na(.)))) %>% melt 
uniques <- mtcars %>% summarise_all(funs(length(unique(.)))) %>% melt 


mtcars %>% summarise_all(funs(n_distinct(.))) %>% melt 


#Build a Data Frame from names of mtcars and add variables with mutate 
DataProfile <- as.data.frame(names(mtcars)) 
DataProfile <- DataProfile %>% mutate(Total = total$value, 
         Nulls = nulls$value, 
         Filled = filled $value, 
         Complete = Filled/Total, 
         Cardinality = uniques$value, 
         Uniqueness = Cardinality/Total, 
         Distinctness = Cardinality/Filled) 
DataProfile 

#These are other attempts with Base R, but they are harder to read and don't play well with summarise_all 
sapply(mtcars, function(x) length(unique(x[!is.na(x)]))) %>% melt 
rapply(mtcars,function(x)length(unique(x))) %>% melt 

Answer 1

的summarise_all()功能可以一次處理一個以上的功能，因此您可以通過做一通，然後格式化你的數據去，你要每個變量「配置文件」的類型鞏固代碼。

library(tidyverse) 

mtcars[2,2] <- NA # Add a null to test completeness 

DataProfile <- mtcars %>% 
    summarise_all(funs("Total" = n(), 
        "Nulls" = sum(is.na(.)), 
        "Filled" = sum(!is.na(.)), 
        "Cardinality" = length(unique(.)))) %>% 
    melt() %>% 
    separate(variable, into = c('variable', 'measure'), sep="_") %>% 
    spread(measure, value) %>% 
    mutate(Complete = Filled/Total, 
     Uniqueness = Cardinality/Total, 
     Distinctness = Cardinality/Filled) 

DataProfile