Hi Md, What I have done is to use the most recent intervening date between the last set of dates if any are there, otherwise the last set of dates. That is what I understand from your description.
Remember that this is a very clunky way to do something like this by adding rows to a data frame, and it is likely to scale up to large data sets badly. df1<-read.table(text="Date Rainfall_Duration 6/14/2016 10 6/15/2016 20 6/17/2016 10 8/16/2016 30 8/19/2016 40 8/21/2016 20 9/4/2016 10", header=TRUE,stringsAsFactors=FALSE) # change the character strings in df2$Date to Date values df1$Date<-as.Date(df1$Date,"%m/%d/%Y") df2<-read.table(text="Date Removal.Rate 6/17/2016 64.7 6/30/2016 22.63 7/14/2016 18.18 8/19/2016 27.87 8/30/2016 23.45 9/2/2016 17.2", header=TRUE,stringsAsFactors=FALSE) # change the character strings in df2$Date to Date values df2$Date<-as.Date(df2$Date,"%m/%d/%Y") df3<-data.frame(Rate.Removal.Date=NULL,Date=NULL,Rainfall_Duration=NULL) df3row<-0 for(i in 1:dim(df2)[1]) { rdrows<-which(df2$Date[i] >= df1$Date & !(df2$Date[i] > df1$Date + 8)) # if there are no dates in df1 within the prior 7 days if(!length(rdrows)) { # first check if at least one date in df1 is less than the df2 # date and is not included in the last set of df1 dates checkrows<-which(df2$Date[i] >= df1$Date) # use the last date greater than the maximum in lastrows if(any(checkrows > lastrows)) rdrows<-max(checkrows[checkrows > lastrows]) # otherwise use the last set else rdrows<-lastrows } # save the current set of dates lastrows<-rdrows # get the number of new rows nrows<-length(rdrows) for(row in 1:nrows) { # set the values in each row df3[row+df3row,1]<-format(df2$Date[i],"%m/%d/%Y") df3[row+df3row,2]<-format(df1$Date[rdrows[row]],"%m/%d/%Y") df3[row+df3row,3]<-df1$Rainfall_Duration[rdrows[row]] } # keep count of the current number of rows df3row<-df3row+nrows } names(df3)<-c("Rate.Removal.Date","Date","Rainfall_Duration") df3 Jim On Thu, Feb 2, 2017 at 4:58 AM, Md Sami Bin Shokrana <samim...@live.com> wrote: > Hi Jim, > > Thank you so much for your help. Your code works great. Could you please > explain your code a bit? One more thing, I am so sorry that I forgot to > mention one more criteria in my post. If it is not much trouble, could you > please help me out with that? I have added a couple more observations > (the bold ones) to each of my data frames which are shown below: > > > The main concept is, > > (i) For a specific date in df2, if no matching dates are available in df1 > within the 7 days range, the code will keep on looking for the latest > available date in df1 with a "Rainfall_Duration" data. For example, in df2, > for *8/30/2016*, there is no "Rainfall_Duration" data available in > df1 within the prior 7 days range. So, I want the code to keep on looking > for dates in df1 until there is an available data for "Rainfall_Duration" > in df1 (in this case which is * 8/21/2016)* . > > > (ii) Additionally, for* 9/2/2016 *(df2), there is no date available in > df1 with a "Rainfall_Duration" data within prior 7 days range. The latest > available data for "Rainfall_Duration" is *8/21/2016*. So, the code will > extract the same result we had for *8/30/2016* in df2. > > In simpler words, i just want the code to keep on looking for data with > "Rainfall_Duraiton" in df1 if there is none available within the prior 7 > days range. Sorry for not mentioning it before. > > > > df1 <- > > Date Rainfall_Duration > 6/14/2016 10 > 6/15/2016 20 > 6/17/2016 10 > 8/16/2016 30 > 8/19/2016 40 > *8/21/2016* *20* *9/4/2016 10* > > > df2 <- > > Date Removal.Rate > 6/17/2016 64.7 > 6/30/2016 22.63 > 7/14/2016 18.18 > 8/19/2016 27.87 > *8/30/2016* *23.45* *9/2/2016 17.2* > > > Expected output: > > > df3 <- > > Rate.Removal.Date Date Rainfall_Duration > 6/17/2016 6/14/2016 10 > 6/17/2016 6/15/2016 20 > 6/17/2016 6/17/2016 10 > 6/30/2016 6/14/2016 10 > 6/30/2016 6/15/2016 20 > 6/30/2016 6/17/2016 10 > 7/14/2016 6/14/2016 10 > 7/14/2016 6/15/2016 20 > 7/14/2016 6/17/2016 10 > 8/19/2016 8/16/2016 30 > 8/19/2016 8/19/2016 40 > *8/30/2016* *8/21/2016* *20* *9/2/2016 8/21/2016 20* > > > Thanks in advance. > > > ------------------------------ > *From:* Jim Lemon <drjimle...@gmail.com> > *Sent:* Wednesday, February 1, 2017 1:18 PM > *To:* Md Sami Bin Shokrana; r-help mailing list > *Subject:* Re: [R] sub-setting rows based on dates in R > > Hi Md, > This kind of clunky, but it might do what you want. > > df1<-read.table(text="Date Rainfall_Duration > 6/14/2016 10 > 6/15/2016 20 > 6/17/2016 10 > 8/16/2016 30 > 8/19/2016 40", > header=TRUE,stringsAsFactors=FALSE) > > df1$Date<-as.Date(df1$Date,"%m/%d/%Y") > > df2<-read.table(text="Date Removal.Rate > 6/17/2016 64.7 > 6/30/2016 22.63 > 7/14/2016 18.18 > 8/19/2016 27.87", > header=TRUE,stringsAsFactors=FALSE) > > df2$Date<-as.Date(df2$Date,"%m/%d/%Y") > > df3<-data.frame(Rate.Removal.Date=NULL,Date=NULL,Rainfall_Duration=NULL) > > df3row<-0 > > for(i in 1:dim(df2)[1]) { > rdrows<-which(df2$Date[i] >= df1$Date & !(df2$Date[i] > df1$Date + 8)) > if(!length(rdrows)) rdrows<-lastrows > lastrows<-rdrows > nrows<-length(rdrows) > for(row in 1:nrows) { > df3[row+df3row,1]<-format(df2$Date[i],"%m/%d/%Y") > df3[row+df3row,2]<-format(df1$Date[rdrows[row]],"%m/%d/%Y") > df3[row+df3row,3]<-df1$Rainfall_Duration[rdrows[row]] > } > df3row<-df3row+nrows > } > > names(df3)<-c("Rate.Removal.Date","Date","Rainfall_Duration") > df3 > > Jim > > On Wed, Feb 1, 2017 at 3:48 AM, Md Sami Bin Shokrana <samim...@live.com> > wrote: > > Hello guys, I am trying to solve a problem in R. I have 2 data frames > which look like this: > > df1 <- > > Date Rainfall_Duration > > 6/14/2016 10 > > 6/15/2016 20 > > 6/17/2016 10 > > 8/16/2016 30 > > 8/19/2016 40 > > > > df2 <- > > Date Removal.Rate > > 6/17/2016 64.7 > > 6/30/2016 22.63 > > 7/14/2016 18.18 > > 8/19/2016 27.87 > > > > I want to look up the dates from df2 in df1 and their corresponding > Rainfall_Duration data. For example, I want to look for the 1st date of df2 > in df1 and subset rows in df1 for that specific date and 7 days prior to > that. additionally, for example: for 6/30/2016 (in df2) there is no dates > available in df1 within it's 7 days range. So, in this case I just want to > extract the results same as it's previous date (6/17/2016) in df2. Same > logic goes for 7/14/2016(df2). > > The output should look like this: > > > > df3<- > > > > Rate.Removal.Date Date Rainfall_Duration > > 6/17/2016 6/14/2016 10 > > 6/17/2016 6/15/2016 20 > > 6/17/2016 6/17/2016 10 > > 6/30/2016 6/14/2016 10 > > 6/30/2016 6/15/2016 20 > > 6/30/2016 6/17/2016 10 > > 7/14/2016 6/14/2016 10 > > 7/14/2016 6/15/2016 20 > > 7/14/2016 6/17/2016 10 > > 8/19/2016 8/16/2016 30 > > 8/19/2016 8/19/2016 40 > > > > I could subset data for the 7 days range. But could not do it when no > dates are available in that range. I have the following code: > > library(plyr) > > library (dplyr) > > df1$Date <- as.Date(df1$Date,format = "%m/%d/%Y") > > df2$Date <- as.Date(df2$Date,format = "%m/%d/%Y") > > > > df3 <- lapply(df2$Date, function(x){ > > filter(df1, between(Date, x-7, x)) > > }) > > > > names(df3) <- as.character(df2$Date) > > bind_rows(df3, .id = "Rate.Removal.Date") > > df3 <- ldply (df3, data.frame, .id = "Rate.Removal.Date") > > > > I hope I could explain my problem properly. I would highly appreciate if > someone can help me out with this code or a new one. Thanks in advance. > > > > > > > > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > > https://stat.ethz.ch/mailman/listinfo/r-help > R-help Info Page - Homepage - SfS – Seminar for Statistics > <https://stat.ethz.ch/mailman/listinfo/r-help> > stat.ethz.ch > The main R mailing list, for announcements about the development of R and > the availability of new code, questions and answers about problems and > solutions using R ... > > > > PLEASE do read the posting guide http://www.R-project.org/ > posting-guide.html > > and provide commented, minimal, self-contained, reproducible code. > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.