3
我有data.frame,我希望得到一個包含給定列Total
如何從一個data.frame列獲得最大價值,並得到所有記錄
Txn_date Cust_no Acct_no cust_type Credit Debit Total
09DEC2013 17382 601298644 I 1500 0 1500
16DEC2013 17382 601298644 I 500 0 500
17DEC2013 17382 601298644 I 0 60 60
18DEC2013 17382 601298644 I 0 200 200
19DEC2013 17382 601298644 I 1500 0 1500
20DEC2013 17382 601298644 I 0 60 60
20DEC2013 17382 601298644 I 0 103 103
30DEC2013 17382 601298644 I 500 0 500
最大值的行所以,我寫了一個簡單的SQL查詢,使用sqldf()
如下解析:
s1<-paste("SELECT Txn_date, Cust_no,Credit,Debit,Total,max(Total) as 'MaxTxnAmt' FROM sample GROUP BY Cust_no")
sample_t1<-sqldf(s1)
這一點讓我
Txn_date Cust_no Acct_no cust_type Credit Debit Total
09DEC2013 17382 601298644 I 1500 0 1500
我得到如上圖所示的精確輸出,如果我使用base - R
功能:
sample_t1<-do.call(rbind,
lapply(split(sample,sample$Cust_no),
function(data) data[which.max(data$Total),]))
,我想知道,我怎麼得到所有這一切都爲列Total
最大值表sample
行。
所需的輸出:
Txn_date Cust_no Acct_no cust_type Credit Debit Total
09DEC2013 17382 601298644 I 1500 0 1500
19DEC2013 17382 601298644 I 1500 0 1500
的樣本數據:
sample <- structure(list(Txn_date = c("09DEC2013", "16DEC2013", "17DEC2013",
"18DEC2013", "19DEC2013", "20DEC2013", "20DEC2013", "30DEC2013"
), Cust_no = c(17382L, 17382L, 17382L, 17382L, 17382L, 17382L,
17382L, 17382L), Acct_no = c("601298644", "601298644", "601298644",
"601298644", "601298644", "601298644", "601298644", "601298644"
), cust_type = c("I", "I", "I", "I", "I", "I", "I", "I"), Credit = c(1500,
500, 0, 0, 1500, 0, 0, 500), Debit = c(0, 0, 60, 200, 0, 60,
103, 0), Total = c(1500, 500, 60, 200, 1500, 60, 103, 500)), .Names = c("Txn_date",
"Cust_no", "Acct_no", "cust_type", "Credit", "Debit", "Total"
), row.names = c(16303L, 29153L, 31174L, 33179L, 35388L, 38750L,
38751L, 53052L), class = "data.frame")