HI,
I have created a dataframe "df" and try to sort it by its date using
the
order() as below:
df<-read.csv(constr,header=T)
sorted.df<-df[order(as.Date(df$Date), decreasing = F),]
print(sorted.df)
The dataframe was sorted, but the output from the command console shows
reserved line order..rather than starting at "1"....it does not really
affect my result, but I want to understand why is that...
Date Open High Low Close Volume Adj.Close
252 2011-01-03 325.64 330.26 324.84 329.57 15897800 328.16
251 2011-01-04 332.44 332.50 328.15 331.29 11038600 329.87
250 2011-01-05 329.55 334.34 329.50 334.00 9125700 332.57
249 2011-01-06 334.72 335.25 332.90 333.73 10729600 332.30
248 2011-01-07 333.99 336.35 331.90 336.12 11140400 334.68
247 2011-01-10 338.83 343.23 337.17 342.45 16020000 340.99
246 2011-01-11 344.88 344.96 339.47 341.64 15861000 340.18
245 2011-01-12 343.25 344.43 342.00 344.42 10806800 342.95
244 2011-01-13 345.16 346.64 343.85 345.68 10599300 344.20
...
...
3 2011-12-28 406.89 408.25 401.34 402.64 8166500 400.92
2 2011-12-29 403.40 405.65 400.51 405.12 7713500 403.39
1 2011-12-30 403.51 406.28 403.49 405.00 6416500 403.27
Any advice would be highly appreciated.
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On Oct 23, 2012, at 9:34 AM, martiny wrote:> HI, > I have created a dataframe "df" and try to sort it by its date using the > order() as below: > > df<-read.csv(constr,header=T) > sorted.df<-df[order(as.Date(df$Date), decreasing = F),] > print(sorted.df) > > The dataframe was sorted, but the output from the command console shows > reserved line order..rather than starting at "1"....it does not really > affect my result, but I want to understand why is that... > > Date Open High Low Close Volume Adj.Close > 252 2011-01-03 325.64 330.26 324.84 329.57 15897800 328.16 > 251 2011-01-04 332.44 332.50 328.15 331.29 11038600 329.87 > 250 2011-01-05 329.55 334.34 329.50 334.00 9125700 332.57 > 249 2011-01-06 334.72 335.25 332.90 333.73 10729600 332.30 > 248 2011-01-07 333.99 336.35 331.90 336.12 11140400 334.68 > 247 2011-01-10 338.83 343.23 337.17 342.45 16020000 340.99 > 246 2011-01-11 344.88 344.96 339.47 341.64 15861000 340.18 > 245 2011-01-12 343.25 344.43 342.00 344.42 10806800 342.95 > 244 2011-01-13 345.16 346.64 343.85 345.68 10599300 344.20 > ... > ... > 3 2011-12-28 406.89 408.25 401.34 402.64 8166500 400.92 > 2 2011-12-29 403.40 405.65 400.51 405.12 7713500 403.39 > 1 2011-12-30 403.51 406.28 403.49 405.00 6416500 403.27It is the dates that were sorted in a non-decreasing order, not the rownames. -- David Winsemius, MD Alameda, CA, USA
As David said, you sorted by Date. But sorting by rownames is not really the point. The point is that rownames are not line numbers. The rownames were assigned when the data frame was created, and then preserved when you sorted. Sometimes, rownames contain meaningful information that is associated with the data in that row, and therefore must be sorted along with the rows. If you want to change the row names to be analogous to line numbers after sorting you can do, for example, rownames(sorted.df) <- seq(nrow(sorted.df)) -Don -- Don MacQueen Lawrence Livermore National Laboratory 7000 East Ave., L-627 Livermore, CA 94550 925-423-1062 On 10/23/12 9:34 AM, "martiny" <my2108 at outlook.com> wrote:>HI, >I have created a dataframe "df" and try to sort it by its date using the >order() as below: > >df<-read.csv(constr,header=T) > sorted.df<-df[order(as.Date(df$Date), decreasing = F),] > print(sorted.df) > >The dataframe was sorted, but the output from the command console shows >reserved line order..rather than starting at "1"....it does not really >affect my result, but I want to understand why is that... > > Date Open High Low Close Volume Adj.Close >252 2011-01-03 325.64 330.26 324.84 329.57 15897800 328.16 >251 2011-01-04 332.44 332.50 328.15 331.29 11038600 329.87 >250 2011-01-05 329.55 334.34 329.50 334.00 9125700 332.57 >249 2011-01-06 334.72 335.25 332.90 333.73 10729600 332.30 >248 2011-01-07 333.99 336.35 331.90 336.12 11140400 334.68 >247 2011-01-10 338.83 343.23 337.17 342.45 16020000 340.99 >246 2011-01-11 344.88 344.96 339.47 341.64 15861000 340.18 >245 2011-01-12 343.25 344.43 342.00 344.42 10806800 342.95 >244 2011-01-13 345.16 346.64 343.85 345.68 10599300 344.20 >... >... >3 2011-12-28 406.89 408.25 401.34 402.64 8166500 400.92 >2 2011-12-29 403.40 405.65 400.51 405.12 7713500 403.39 >1 2011-12-30 403.51 406.28 403.49 405.00 6416500 403.27 > >Any advice would be highly appreciated. > > > >-- >View this message in context: >http://r.789695.n4.nabble.com/After-sorting-a-dataframe-by-date-tp4647173. >html >Sent from the R help mailing list archive at Nabble.com. > >______________________________________________ >R-help at r-project.org mailing list >https://stat.ethz.ch/mailman/listinfo/r-help >PLEASE do read the posting guide >http://www.R-project.org/posting-guide.html >and provide commented, minimal, self-contained, reproducible code.