我试图将此数据框的子集仅包含具有＆＃34; kw＆＃34;的行。在UOM列中，但结果数据框是空的（它没有找到任何＆＃34; kw＆＃34;显然有......）有人有任何想法吗？
> source<-read.csv("C:\\Users\\mcan\\Desktop\\Analysis\\Reduced Data.csv",header=TRUE, sep=",",stringsAsFactors = FALSE) #open
> str(source)
'data.frame': 1048575 obs. of 12 variables:
$ Location.. : int 12345 12345 12345 12345 12345 12345 12345 12345 ...
$ Vendor.Name : chr "Alabama Power" "Alabama Power" "Alabama Power" "Alabama Power" ...
$ Bill.Month : chr "8/01/2015" "5/01/2015" "12/01/2016" "11/01/2015" ...
$ Bill.Date : chr "8/27/2015" "5/28/2015" "12/28/2016" "11/24/2015" ...
$ Service.Begin.Date : chr "7/29/2015" "4/29/2015" "11/29/2016" "10/27/2015" ...
$ Service.End.Date : chr "8/26/2015" "5/28/2015" "12/28/2016" "11/24/2015" ...
$ Service.Days : int 29 30 30 29 33 33 33 32 29 32 ...
$ Service.Description: chr "Elec Off Peak" "Elec Adjustment" "Elec Adjustment" "Elec Off Peak" ...
$ Service.Alias : chr "Energy - Off Peak" "Fuel Cost Adjustment - On Peak" "Contribution" "Off Peak Kwh Usage" ...
$ Billed.Quantity : chr "60,000" "0.000" "0.000" "0.000" ...
$ UOM : chr "kWh" "" "" "kWh" ...
$ Cost : chr "$3,000.10 " "($20.090)" "$41.120 " "$0.000 " ...
> library("sqldf")
> library("data.table")
> data<-subset(source,select = -c(Vendor.Name,Bill.Month,Bill.Date,Service.Description,Cost))
> head(data)
Location.. Service.Begin.Date Service.End.Date Service.Days Service.Alias Billed.Quantity UOM
1 12345 7/29/2015 8/26/2015 29 Energy - Off Peak 60,000.000 kWh
2 12345 4/29/2015 5/28/2015 30 Fuel Cost Adjustment - On Peak 0.000
3 12345 11/29/2016 12/28/2016 30 Contribution 0.000
4 12345 10/27/2015 11/24/2015 29 Off Peak Kwh Usage 0.000 kWh
5 12345 12/27/2014 1/28/2015 33 Kw Usage 0.000 Kw
6 12345 12/27/2014 1/28/2015 33 On-Peak Demand Charge 190.000 Kw
> newdata<-subset(data,UOM=="kw")
> newdata
[1] Location.. Service.Begin.Date Service.End.Date Service.Days Service.Alias Billed.Quantity UOM
<0 rows> (or 0-length row.names)
答案 0 :(得分：0)
谢谢@ mako212
newdata<-subset(data,UOM=="Kw")