I have the following data set: Country Product Price Year_Month AE 1 20 201204 DE 1 20 201204 CN 1 28 201204 AE 2 28 201204 DE 2 28 201204 CN 2 22 201204 AE 3 28 201204 CN 3 28 201204 AE 1 20 201205 DE 1 20 201205 CN 1 28 201205 AE 2 28 201205 DE 2 28 201205 I want to create the one more column which is "The average price of the product in other areas". in other word, for each month, for each product, I calculate the average of such product in the other area. I want sth like: Country Product Price Year_Month Price_average_In_Other_area AE 1 20 201204 14 AE 2 28 201204 25 Please avoid the three for loop, I have tried and it never end. I have 1070427 rows. Is there better way to speed up my program? [[alternative HTML version deleted]]
Hi I do not see any solution without loops but maybe others find it. I think that you can do it in one loop. Best structure for loop will be list. In each cycle you will compute matrix with diagonal NA mat<-matrix(1,nrow=number of items, ncol=number of items) diag(mat) <- NA apply(price chunk * mat, 2, mean, na.rm=T) So when I named your example as temp I get fac <- interaction(factor(temp$Product), factor(temp$Year_Month), drop=T) lll <- split(temp, fac) for( i in 1:length(lll)) { mat <- matrix(1, nrow=nrow(lll[[i]]), ncol= nrow(lll[[i]])) diag(mat) <- NA lll[[i]]$others <- apply(mat*lll[[i]][,3], 2, mean, na.rm=T) }> lll$`1.201204` Country Product Price Year_Month others 1 AE 1 20 201204 24 2 DE 1 20 201204 24 3 CN 1 28 201204 20 $`2.201204` Country Product Price Year_Month others 4 AE 2 28 201204 25 5 DE 2 28 201204 25 6 CN 2 22 201204 28 $`3.201204` Country Product Price Year_Month others 7 AE 3 28 201204 28 8 CN 3 28 201204 28 $`1.201205` Country Product Price Year_Month others 9 AE 1 20 201205 24 10 DE 1 20 201205 24 11 CN 1 28 201205 20 $`2.201205` Country Product Price Year_Month others 12 AE 2 28 201205 28 13 DE 2 28 201205 28 I did not check speed but it shall be OK. Regards Petr> -----Original Message----- > From: r-help-bounces at r-project.org [mailto:r-help-bounces at r- > project.org] On Behalf Of Lingyi Ma > Sent: Friday, August 01, 2014 1:42 PM > To: r-help at r-project.org > Subject: [R] How to avoid the three loops in R? > > I have the following data set: > > Country Product Price Year_Month > AE 1 20 201204 > DE 1 20 201204 > CN 1 28 201204 > AE 2 28 201204 > DE 2 28 201204 > CN 2 22 201204 > AE 3 28 201204 > CN 3 28 201204 > AE 1 20 201205 > DE 1 20 201205 > CN 1 28 201205 > AE 2 28 201205 > DE 2 28 201205 > > I want to create the one more column which is "The average price of the > product in other areas". > in other word, for each month, for each product, I calculate the > average of such product in the other area. > > I want sth like: > > Country Product Price Year_Month Price_average_In_Other_area > AE 1 20 201204 14 > AE 2 28 201204 25 > > Please avoid the three for loop, I have tried and it never end. I have > 1070427 rows. Is there better way to speed up my program? > > [[alternative HTML version deleted]] > > ______________________________________________ > 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.________________________________ Tento e-mail a jak?koliv k n?mu p?ipojen? dokumenty jsou d?v?rn? a jsou ur?eny pouze jeho adres?t?m. Jestli?e jste obdr?el(a) tento e-mail omylem, informujte laskav? neprodlen? jeho odes?latele. Obsah tohoto emailu i s p??lohami a jeho kopie vyma?te ze sv?ho syst?mu. Nejste-li zam??len?m adres?tem tohoto emailu, nejste opr?vn?ni tento email jakkoliv u??vat, roz?i?ovat, kop?rovat ?i zve?ej?ovat. Odes?latel e-mailu neodpov?d? za eventu?ln? ?kodu zp?sobenou modifikacemi ?i zpo?d?n?m p?enosu e-mailu. 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On Fri, Aug 1, 2014 at 6:41 AM, Lingyi Ma <lingyi.ma at gmail.com> wrote:> I have the following data set: > > Country Product Price Year_Month > AE 1 20 201204 > DE 1 20 201204 > CN 1 28 201204 > AE 2 28 201204 > DE 2 28 201204 > CN 2 22 201204 > AE 3 28 201204 > CN 3 28 201204 > AE 1 20 201205 > DE 1 20 201205 > CN 1 28 201205 > AE 2 28 201205 > DE 2 28 201205 > > I want to create the one more column which is "The average price of the > product in other areas". > in other word, for each month, for each product, I calculate the average of > such product in the other area. > > I want sth like: > > Country Product Price Year_Month Price_average_In_Other_area > AE 1 20 201204 14 > AE 2 28 201204 25The output above looks wrong. The Price_average_In_Other_area for AE, product 1 should be 24? My possible solution: # Initialize data.frame & call it "x". Country <- c("AE","DE","CN","AE","DE","CN","AE","CN","AE","DE","CN","AE","DE"); Product <- c(1,1,1,2,2,2,3,3,1,1,1,2,2); Price <- c(20,20,28,28,28,22,28,28,20,20,28,28,28); Year_Month <- c(201204,201204,201204,201204,201204,201204,201204,201204,201205,201205,201205,201205,201205); x <- data.frame(Country,Product,Price,Year_Month,stringsAsFactors=FALSE); # # library("dplyr"); # # Get the total Price of all Products and number of Products for each Product & Year_Month" y <- summarize(group_by(x, Product, Year_Month),sumPrice=sum(Price),NoPrice=length(Price)); # # Merge the above data back into the original data.frame, based on # Product and Year_Month (similar to SQL inner join). x <- merge(x=x,y=y); # # Now calculate the "other area" average by subtracting the cost in this area # from the total cost in all areas and divide by the number of areas, minus one. # Please note that if a Product and Year_Month is unique, i.e. no other areas # for this Product & Year_Month, this will try to divide by zero. # This gives "Inf" as an answer. x$Prive_average_In_Other_area <- (x$sumPrice-x$Price)/(x$NoPrice-1); # Possible alternate to handle above consideration x$Avg_other <- ifelse(x$NoPrice>1,(x$sumPrice-x$Price)/(x$NoPrice-1),NA);> > Please avoid the three for loop, I have tried and it never end. I have > 1070427 rows. Is there better way to speed up my program?-- There is nothing more pleasant than traveling and meeting new people! Genghis Khan Maranatha! <>< John McKown