[R] Need to merge multiple data frames with time stamp

jim holtman jholtman at gmail.com
Fri Oct 18 16:19:42 CEST 2013


You at least need to provide a subset of what the data looks likes.
Since you are merging on 'time', if there are not the same times in
each set, then you will have missing values.  For example, in the
merges that you are doing, have you looked at the size of the
resulting object compared to the two that you are merging? That would
give you and idea as to how much you might be missing.

Also is your time as POSIXct? If so, are there fractional seconds in
the data?  If you had provided some data, some of these questions
would be answered.

Jim Holtman
Data Munger Guru

What is the problem that you are trying to solve?
Tell me what you want to do, not how you want to do it.


On Fri, Oct 18, 2013 at 7:37 AM,  <Sandeep.Sampara at ril.com> wrote:
> Hi,
>
>
>
> I'm trying to combine 15 different data frames but all have time field as
> common. But the thing is time intervals are different (like min's and
> sec's).
>
> So I have to check the common time from all the 15 data frames and merge it
> to a single data frame and then export it to excel or csv.
>
> I tried with below query but it's not giving exact output. It's almost 5
> year of data, but its giving output for 3months only.
>
> Please help with your query to get my output.
>
>
>
> a <- merge(MA2DHPA,MA2DHPB,by="IP_Trend_Time")
>
> b <- merge(MA2UCPA,MA2UCPB,by="IP_Trend_Time")
>
> c <- merge(MA2DCPA,MA2DCPB,by="IP_Trend_Time")
>
> d <- merge(MA2DHTA,MA2DHTB,by="IP_Trend_Time")
>
> e <- merge(MA2UCTA,MA2UCTB,by="IP_Trend_Time")
>
> f <- merge(MA2DCTA,MA2DCTB,by="IP_Trend_Time")
>
> g <- merge(MA2CP,MA2CPS,by="IP_Trend_Time")
>
> h <- MA2AP
>
>
>
> x <- merge(a,b,by="IP_Trend_Time")
>
> y <- merge(c,d,by="IP_Trend_Time")
>
> z <- merge(e,f,by="IP_Trend_Time")
>
> w <- merge(g,h,by="IP_Trend_Time")
>
>
>
> x1 <- merge(x,y,by="IP_Trend_Time")
>
> y1 <- merge(z,w,by="IP_Trend_Time")
>
>
>
> MA2 <- merge(x1,y1,by="IP_Trend_Time")
>
>
>
> Regards,
>
> Sandeep S|IT&C,
> Reliance Industries Limited (E&P) | Onshore Terminal | Gadimoga
> *  +91 884 2977066 / 9908130749
>
>
>
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