Wow, Mr Petr. The placing of diff(fyear1) was very clever indeed. Just to understand the steps intended by you-
exp(diff(log(sales1))/diff(fyear1))- 1) = exp(((log(sales1(t)/sales1(t-1)))/(fyear1(t)-fyear(t-1)))-1) = exp(log(sales(t)/sales(t-1))^(1/(delta(fyear1))))-1 = ((sales(t)/(sales(t-1)))^(1/(delta(fyear1)))-1 This gives the CAGR, which saves some precious data-points (in my dataset, it may prove a big boon). I spent a significant amount of time today to figure out something like this, which you did so easily. Many Thanks, Brijesh On Thu, Dec 15, 2016 at 7:21 PM, PIKAL Petr <petr.pi...@precheza.cz> wrote: > Hi > > Maybe you does not need if or ifelse but just divide by years difference. > > d2<-ddply(df1,"co_code1",transform, > growth=c(NA,exp(diff(log(sales1))/diff(fyear1))- 1)*100) > > Cheers > Petr > >> -----Original Message----- >> From: R-help [mailto:r-help-boun...@r-project.org] On Behalf Of Berend >> Hasselman >> Sent: Thursday, December 15, 2016 1:18 PM >> To: Brijesh Mishra <brijeshkmis...@gmail.com> >> Cc: r-help mailing list <r-help@r-project.org> >> Subject: Re: [R] Computing growth rate >> >> >> > On 15 Dec 2016, at 04:40, Brijesh Mishra <brijeshkmis...@gmail.com> >> wrote: >> > >> > Hi, >> > >> > I am trying to calculate growth rate (say, sales, though it is to be >> > computed for many variables) in a panel data set. Problem is that I >> > have missing data for many firms for many years. To put it simply, I >> > have created this short dataframe (original df id much bigger) >> > >> > df1<-data.frame(co_code1=rep(c(1100, 1200, 1300), each=7), >> > fyear1=rep(1990:1996, 3), sales1=rep(seq(1000,1600, by=100),3)) >> > >> > # this gives me >> > co_code1 fyear1 sales1 >> > 1 1100 1990 1000 >> > 2 1100 1991 1100 >> > 3 1100 1992 1200 >> > 4 1100 1993 1300 >> > 5 1100 1994 1400 >> > 6 1100 1995 1500 >> > 7 1100 1996 1600 >> > 8 1200 1990 1000 >> > 9 1200 1991 1100 >> > 10 1200 1992 1200 >> > 11 1200 1993 1300 >> > 12 1200 1994 1400 >> > 13 1200 1995 1500 >> > 14 1200 1996 1600 >> > 15 1300 1990 1000 >> > 16 1300 1991 1100 >> > 17 1300 1992 1200 >> > 18 1300 1993 1300 >> > 19 1300 1994 1400 >> > 20 1300 1995 1500 >> > 21 1300 1996 1600 >> > >> > # I am now removing a couple of rows >> > df1<-df1[-c(5, 8), ] >> > # the result is >> > co_code1 fyear1 sales1 >> > 1 1100 1990 1000 >> > 2 1100 1991 1100 >> > 3 1100 1992 1200 >> > 4 1100 1993 1300 >> > 6 1100 1995 1500 >> > 7 1100 1996 1600 >> > 9 1200 1991 1100 >> > 10 1200 1992 1200 >> > 11 1200 1993 1300 >> > 12 1200 1994 1400 >> > 13 1200 1995 1500 >> > 14 1200 1996 1600 >> > 15 1300 1990 1000 >> > 16 1300 1991 1100 >> > 17 1300 1992 1200 >> > 18 1300 1993 1300 >> > 19 1300 1994 1400 >> > 20 1300 1995 1500 >> > 21 1300 1996 1600 >> > # so 1994 for co_code1 1100 and 1990 for co_code1 1200 have been >> > removed. If I try, >> > d<-ddply(df1,"co_code1",transform, growth=c(NA,exp(diff(log(sales1)))- >> 1)*100) >> > >> > # this apparently gives wrong results for the year 1995 (as shown >> > below) as growth rates are computed considering yearly increment. >> > >> > co_code1 fyear1 sales1 growth >> > 1 1100 1990 1000 NA >> > 2 1100 1991 1100 10.000000 >> > 3 1100 1992 1200 9.090909 >> > 4 1100 1993 1300 8.333333 >> > 5 1100 1995 1500 15.384615 >> > 6 1100 1996 1600 6.666667 >> > 7 1200 1991 1100 NA >> > 8 1200 1992 1200 9.090909 >> > 9 1200 1993 1300 8.333333 >> > 10 1200 1994 1400 7.692308 >> > 11 1200 1995 1500 7.142857 >> > 12 1200 1996 1600 6.666667 >> > 13 1300 1990 1000 NA >> > 14 1300 1991 1100 10.000000 >> > 15 1300 1992 1200 9.090909 >> > 16 1300 1993 1300 8.333333 >> > 17 1300 1994 1400 7.692308 >> > 18 1300 1995 1500 7.142857 >> > 19 1300 1996 1600 6.666667 >> > # I thought of using the formula only when the increment of fyear1 is >> > only 1 while in a co_code1, by using this formula >> > >> > d<-ddply(df1, >> > "co_code1", >> > transform, >> > if(diff(fyear1)==1){ >> > growth=(exp(diff(log(df1$sales1)))-1)*100 >> > } else{ >> > growth=NA >> > }) >> > >> > But, this doesn't work. I am getting the following error. >> > >> > In if (diff(fyear1) == 1) { : >> > the condition has length > 1 and only the first element will be used >> > (repeated a few times). >> > >> > # I have searched for a solution, but somehow couldn't get one. Hope >> > that some kind soul will guide me here. >> > >> >> In your case use ifelse() as explained by Rui. >> But it can be done more easily since the fyear1 and co_code1 are >> synchronized. >> Add a new column to df1 like this >> >> df1$growth <- c(NA, >> ifelse(diff(df1$fyear1)==1, >> (exp(diff(log(df1$sales1)))-1)*100, >> NA >> ) >> ) >> >> and display df1. From your request I cannot determine if this is what you >> want. >> >> regards, >> >> Berend Hasselman >> >> ______________________________________________ >> 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. > > ________________________________ > Tento e-mail a jakékoliv k němu připojené dokumenty jsou důvěrné a jsou > určeny pouze jeho adresátům. > Jestliže jste obdržel(a) tento e-mail omylem, informujte laskavě neprodleně > jeho odesílatele. Obsah tohoto emailu i s přílohami a jeho kopie vymažte ze > svého systému. > Nejste-li zamýšleným adresátem tohoto emailu, nejste oprávněni tento email > jakkoliv užívat, rozšiřovat, kopírovat či zveřejňovat. > Odesílatel e-mailu neodpovídá za eventuální škodu způsobenou modifikacemi či > zpožděním přenosu e-mailu. > > V případě, že je tento e-mail součástí obchodního jednání: > - vyhrazuje si odesílatel právo ukončit kdykoliv jednání o uzavření smlouvy, > a to z jakéhokoliv důvodu i bez uvedení důvodu. > - a obsahuje-li nabídku, je adresát oprávněn nabídku bezodkladně přijmout; > Odesílatel tohoto e-mailu (nabídky) vylučuje přijetí nabídky ze strany > příjemce s dodatkem či odchylkou. > - trvá odesílatel na tom, že příslušná smlouva je uzavřena teprve výslovným > dosažením shody na všech jejích náležitostech. > - odesílatel tohoto emailu informuje, že není oprávněn uzavírat za společnost > žádné smlouvy s výjimkou případů, kdy k tomu byl písemně zmocněn nebo písemně > pověřen a takové pověření nebo plná moc byly adresátovi tohoto emailu > případně osobě, kterou adresát zastupuje, předloženy nebo jejich existence je > adresátovi či osobě jím zastoupené známá. > > This e-mail and any documents attached to it may be confidential and are > intended only for its intended recipients. > If you received this e-mail by mistake, please immediately inform its sender. > Delete the contents of this e-mail with all attachments and its copies from > your system. > If you are not the intended recipient of this e-mail, you are not authorized > to use, disseminate, copy or disclose this e-mail in any manner. > The sender of this e-mail shall not be liable for any possible damage caused > by modifications of the e-mail or by delay with transfer of the email. > > In case that this e-mail forms part of business dealings: > - the sender reserves the right to end negotiations about entering into a > contract in any time, for any reason, and without stating any reasoning. > - if the e-mail contains an offer, the recipient is entitled to immediately > accept such offer; The sender of this e-mail (offer) excludes any acceptance > of the offer on the part of the recipient containing any amendment or > variation. > - the sender insists on that the respective contract is concluded only upon > an express mutual agreement on all its aspects. > - the sender of this e-mail informs that he/she is not authorized to enter > into any contracts on behalf of the company except for cases in which he/she > is expressly authorized to do so in writing, and such authorization or power > of attorney is submitted to the recipient or the person represented by the > recipient, or the existence of such authorization is known to the recipient > of the person represented by the recipient. ______________________________________________ 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.
