Re: [R] Conditional operation on multiple columns from two data frames

2008-12-28 Thread jim holtman
Merge will give you an output like below and you should be able to find the value you need: > merge(df1, df2, by='ID', all=TRUE) ID Date.x y.x x.x Date.y y.y x.y 1 1NANA 2007-05-31 23:00:00 -20.82907 217.7022 2 1

Re: [R] Conditional operation on multiple columns from two data frames

2008-12-28 Thread Peter Dalgaard
tsippel wrote: The suggestion below was made. df1$Date <- as.Date(df1$Date) df2$Date <- as.Date(df2$Date) ifelse(df1$ID==df2$ID & df1$Date-df2$Date<0.5,df1$y-df2$y, NA) However, because my dataframe rows do not align, I need the conditionals to be tested on every combination of cells. I'm s

Re: [R] Conditional operation on multiple columns from two data frames

2008-12-28 Thread tsippel
The suggestion below was made. df1$Date <- as.Date(df1$Date) df2$Date <- as.Date(df2$Date) ifelse(df1$ID==df2$ID & df1$Date-df2$Date<0.5,df1$y-df2$y, NA) However, because my dataframe rows do not align, I need the conditionals to be tested on every combination of cells. I'm starting to think

Re: [R] Conditional operation on multiple columns from two data frames

2008-12-27 Thread Tim Sippel
Sorry...I was unaware I needed to 'deput' to deparse data examples into a useful format. The data examples I provided initially are deparsed below: df1<- list(ID = c(2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3), Date = c("2007-05-30 18:48:20", "2007-05-30 20:21:56", "2007-06-02 09:39:58", "2007-06-02 1

[R] Conditional operation on multiple columns from two data frames

2008-12-27 Thread Tim Sippel
Hi- I have two data frames for which I wish to conditionally subtract the values of one dataframe from the other. I want to subtract df1$x from df2$x when their id is equal and the absolute value of difference between the dates is 12 hours or less. If there is no match of equal id's and dates le