Re: [R] Help finding first value in a BY group

ware wdunlap tibco.com > -Original Message- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On > Behalf > Of Marc Schwartz > Sent: Friday, March 15, 2013 11:57 AM > To: arun > Cc: R help > Subject: Re: [R] Help finding first value in

Re: [R] Help finding first value in a BY group

; > #or > library(plyr) > ddply(PeriodSKUForecast,.(SKU),summarise, Forecast=head(Forecast,1)) > # SKU Forecast > #1 A1 99 > #2 K2 207 > #3 X4 63 > A.K. > > > > > - Original Message - > From: Barry King > To: r-help@r-project.or

Re: [R] Help finding first value in a BY group

(PeriodSKUForecast,.(SKU),summarise, Forecast=head(Forecast,1)) #  SKU Forecast #1  A1   99 #2  K2  207 #3  X4   63 A.K. - Original Message - From: Barry King To: r-help@r-project.org Cc: Sent: Friday, March 15, 2013 1:30 PM Subject: [R] Help finding first value in a BY group I have a

[R] Help finding first value in a BY group

I have a large Excel file with SKU numbers (stock keeping units) and forecasts which can be mimicked with the following: Period <- c(1, 2, 3, 1, 2, 3, 4, 1, 2) SKU <- c("A1","A1","A1","X4","X4","X4","X4","K2","K2") Forecast <- c(99, 103, 128, 63, 69, 72, 75, 207, 201) PeriodSKUForecast <- data.fra