Dear 'HTH' R friends
I have a small dataframe as given below. I need to sort this database based on
date in a decending order. I am not sure whether I have defined the date column
in a proper format.
mydat<-data.frame(date = (c("1/31/2010", "2/28/2010", "3/31/2010", "4/30/2010",
"5/31/2010", "6/30/2010", "7/31/2010", "8/31/2010", "9/30/2010", "10/31/2010",
"11/30/2010", "12/28/2010")), total=c(429, 25, 239, 99, 100, 96, 18, 21, 10,
76, 101, 81), newspapers=c(103, 4, 37, 109, 52, 87, 17, 13, 10, 56, 87, 14))
> mydat
date total newspapers
1 1/31/2010 429 103
2 2/28/2010 25 4
3 3/31/2010 239 37
4 4/30/2010 99 109
5 5/31/2010 100 52
6 6/30/2010 96 87
7 7/31/2010 18 17
8 8/31/2010 21 13
9 9/30/2010 10 10
10 10/31/2010 76 56
11 11/30/2010 101 87
12 12/28/2010 81 14
I need to sort this data in a DESCENDING order based on a date. I.e. I need to
have
date total newspapers
12/28/2010 81 14
11/30/2010 101 87
10/31/2010 76 56
.................................
..................................
1/31/2010 429 103
When I tried
mydat.sort <- mydat[order(mydat$date)]
> mydat.sort <- mydat[order(mydat$date)]
Error in `[.data.frame`(mydat, order(mydat$date)) : undefined columns selected
Kindly guide
Vincy Pyne
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