Dear all, I have a lot of problems on R-programming. for example my csv. file is .. Date wrfRH wrfsolar wrfwindspeed wrfrain wrftd wrfta 21/10/2010 92.97 22.11 53.27 0 1546.337861 61.00852664 22/10/2010 87.35 21.99 40.89 0 1300.408288 62.85352227 23/10/2010 88.38 21.71 28.04 0.01 1381.768284 54.80594493 24/10/2010 92.32 15.45 22.38 0.51 1113.90981 39.46573663 25/10/2010 93.42 21.59 35.5 0.52 868.4895334 28.42952321 26/10/2010 93.38 20.15 42.58 0.07 1404.722837 40.29300856 i calculate the ratio of wrfRH/wrfsolar for each day. that is Date wrfRH wrfsolar wrfwindspeed wrfrain wrftd wrfta ratio 21/10/2010 92.97 22.11 53.27 0 1546.337861 61.00852664 XXXX 22/10/2010 87.35 21.99 40.89 0 1300.408288 62.85352227 YYYY 23/10/2010 88.38 21.71 28.04 0.01 1381.768284 54.80594493 ZZZZ 24/10/2010 92.32 15.45 22.38 0.51 1113.90981 39.46573663 AAAA 25/10/2010 93.42 21.59 35.5 0.52 868.4895334 28.42952321 BBBB 26/10/2010 93.38 20.15 42.58 0.07 1404.722837 40.29300856 CCCC how to add new column in the original file ? Anyone can help me?! -- View this message in context: http://r.789695.n4.nabble.com/Adding-a-column-into-the-file-tp4632093.html Sent from the R help mailing list archive at Nabble.com.
Hi, On Fri, Jun 1, 2012 at 12:27 PM, pigpigmeow <glorykwok at hotmail.com> wrote:> Dear all, > I have a lot of problems on R-programming. > for example > my csv. file is .. > Date ? ? ? ? ? ? ? ? ?wrfRH wrfsolar wrfwindspeed wrfrain wrftd wrfta > 21/10/2010 92.97 22.11 53.27 0 1546.337861 61.00852664 > 22/10/2010 87.35 21.99 40.89 0 1300.408288 62.85352227 > 23/10/2010 88.38 21.71 28.04 0.01 1381.768284 54.80594493 > 24/10/2010 92.32 15.45 22.38 0.51 1113.90981 39.46573663 > 25/10/2010 93.42 21.59 35.5 0.52 868.4895334 28.42952321 > 26/10/2010 93.38 20.15 42.58 0.07 1404.722837 40.29300856Did you read it into R with read.table() or read.csv()?> i calculate the ratio of wrfRH/wrfsolar for each day.And got XXXX, YYYY, ZZZZ - I don't think so. Is that part of the question? myratio <- with(mydata, wrfRH/wrfsolar) might do it.> > that is > Date ? ? ? ? ? ? ? ? ?wrfRH wrfsolar wrfwindspeed wrfrain wrftd wrfta ratio > 21/10/2010 92.97 22.11 53.27 0 1546.337861 61.00852664 ?XXXX > 22/10/2010 87.35 21.99 40.89 0 1300.408288 62.85352227 ?YYYY > 23/10/2010 88.38 21.71 28.04 0.01 1381.768284 54.80594493 ZZZZ > 24/10/2010 92.32 15.45 22.38 0.51 1113.90981 39.46573663 AAAA > 25/10/2010 93.42 21.59 35.5 0.52 868.4895334 28.42952321 BBBB > 26/10/2010 93.38 20.15 42.58 0.07 1404.722837 40.29300856 ?CCCC > > how to add new column in the original file ? Anyone can help me?!First add it to your data frame with cbind(). Then you can use write.table() or write.csv() to overwrite your original file, if you really want to do that. And please, as I already recommended, read some of the excellent introductory material available online. This is very basic stuff, and some evidence that you'd tried to work it out on your would would encourage the volunteers here to help you out. Reading the posting guide wouldn't be a bad idea either. Sarah -- Sarah Goslee http://www.functionaldiversity.org
On Jun 1, 2012, at 12:27 PM, pigpigmeow wrote:> Dear all, > I have a lot of problems on R-programming. > for example > my csv. file is ..That certainly does not look like any csv file I have ever seen.> Date wrfRH wrfsolar wrfwindspeed wrfrain wrftd wrfta > 21/10/2010 92.97 22.11 53.27 0 1546.337861 61.00852664 > 22/10/2010 87.35 21.99 40.89 0 1300.408288 62.85352227 > 23/10/2010 88.38 21.71 28.04 0.01 1381.768284 54.80594493 > 24/10/2010 92.32 15.45 22.38 0.51 1113.90981 39.46573663 > 25/10/2010 93.42 21.59 35.5 0.52 868.4895334 28.42952321 > 26/10/2010 93.38 20.15 42.58 0.07 1404.722837 40.29300856 > i calculate the ratio of wrfRH/wrfsolar for each day. >If you are confused in your terminology, and you really have a data.frame created by read.table, then adding a column to an existing data.frame , say the ratio of wrftd divided by wrfta, is really simple: dfrm$ratio <- with dfrm, wrftd/wrfta)> that is > Date wrfRH wrfsolar wrfwindspeed wrfrain wrftd > wrfta ratio > 21/10/2010 92.97 22.11 53.27 0 1546.337861 61.00852664 XXXX > 22/10/2010 87.35 21.99 40.89 0 1300.408288 62.85352227 YYYY > 23/10/2010 88.38 21.71 28.04 0.01 1381.768284 54.80594493 ZZZZ > 24/10/2010 92.32 15.45 22.38 0.51 1113.90981 39.46573663 AAAA > 25/10/2010 93.42 21.59 35.5 0.52 868.4895334 28.42952321 BBBB > 26/10/2010 93.38 20.15 42.58 0.07 1404.722837 40.29300856 CCCC > > how to add new column in the original file ? Anyone can help me?! > > -- > View this message in context: http://r.789695.n4.nabble.com/Adding-a-column-into-the-file-tp4632093.html > Sent from the R help mailing list archive at Nabble.com. >David Winsemius, MD West Hartford, CT
On Fri, 1 Jun 2012 09:27:58 -0700 (PDT) pigpigmeow <glorykwok at hotmail.com> wrote:> Dear all, > I have a lot of problems on R-programming. > for example > my csv. file is .. > Date wrfRH wrfsolar wrfwindspeed wrfrain wrftd wrfta > 21/10/2010 92.97 22.11 53.27 0 1546.337861 61.00852664 > 22/10/2010 87.35 21.99 40.89 0 1300.408288 62.85352227 > 23/10/2010 88.38 21.71 28.04 0.01 1381.768284 54.80594493 > 24/10/2010 92.32 15.45 22.38 0.51 1113.90981 39.46573663 > 25/10/2010 93.42 21.59 35.5 0.52 868.4895334 28.42952321 > 26/10/2010 93.38 20.15 42.58 0.07 1404.722837 40.29300856 > i calculate the ratio of wrfRH/wrfsolar for each day. > > that is > Date wrfRHwrfwindspeed wrfrain wrftd wrfta ratio> 21/10/2010 92.97 22.11 53.27 0 1546.337861 61.00852664 XXXX > 22/10/2010 87.35 21.99 40.89 0 1300.408288 62.85352227 YYYY > 23/10/2010 88.38 21.71 28.04 0.01 1381.768284 54.80594493 ZZZZ > 24/10/2010 92.32 15.45 22.38 0.51 1113.90981 39.46573663 AAAA > 25/10/2010 93.42 21.59 35.5 0.52 868.4895334 28.42952321 BBBB > 26/10/2010 93.38 20.15 42.58 0.07 1404.722837 40.29300856 CCCC > > how to add new column in the original file ? Anyone can help me?! >First, that is not a csv file. Your delimiter is a space. Second, it appears that the first and second records contain two spaces between the wrtfa column and the ratio column. Since you don't provide an example how how you actually read the data table into R, there's no way to say what else might be wrong. If you specify an escaped space as the delimiter, the read should fail at about the third line. Now, if you use R to calculate the ratio the story is different. I would guess you simply want to join the calulated field to your data frame: To move the new data to a data frame, calculate the new variable and then assemble the new data frame: ratio <- dat$wrfRH/dat$wrfsolar then newdataframe <- data.frame(dat, ratio) which should yield what I believe you want. That of course assumes that what you really want to do is simply add the new column of calculated values to the original data. There also any number of very helpful books about R that can probably help.
On Jun 1, 2012, at 4:08 PM, David Winsemius wrote:> > On Jun 1, 2012, at 12:27 PM, pigpigmeow wrote: > >> Dear all, >> I have a lot of problems on R-programming. >> for example my csv. file is .. > > That certainly does not look like any csv file I have ever seen. > >> Date wrfRH wrfsolar wrfwindspeed wrfrain wrftd wrfta >> 21/10/2010 92.97 22.11 53.27 0 1546.337861 61.00852664 >>>> i calculate the ratio of wrfRH/wrfsolar for each day. >> > > If you are confused in your terminology, and you really have a > data.frame created by read.table, then adding a column to an > existing data.frame , say the ratio of wrftd divided by wrfta, is > really simple: > > dfrm$ratio <- with dfrm, wrftd/wrfta)And that of course should have been : dfrm$ratio <- with( dfrm, wrftd/wrfta) -- David Winsemius, MD West Hartford, CT