[R] nested for loop with data table

Sat May 6 18:39:41 CEST 2017

Thank you Jeff. Your idea, as i mentioned on my previous posting, did
indeed work. I read somewhere that both data table dplyr do great many
things and i plan to learn both as much as i can. Suggestions on this list
either get you the answer you are looking for or give you lead to an answer.

Thanks again

On Thu, May 4, 2017 at 12:04 AM, Jeff Newmiller <jdnewmil at dcn.davis.ca.us>
wrote:

> You seem to be unaware of the "aggregate" data processing concept. There
> are many ways to accomplish aggregation, but I am not fluent in data.table
> methods but knowing the concept is the first step.
>
> Perhaps look closely at [1], or Google for data table aggregation yourself?
>
> [1] https://www.r-bloggers.com/efficient-aggregation-and-
> more-using-data-table/amp/
> --
> Sent from my phone. Please excuse my brevity.
>
> On May 3, 2017 8:17:21 AM PDT, Ek Esawi <esawiek at gmail.com> wrote:
> >Thank you both Boris and Jim. Thank you, Boris, for advising to read
> >the
> >posting guide; I had and I just did.
> >
> >Jim’s idea is exactly what I want; however, I could not pass sset1,
> >sset2,
> >etc. to the j nested loop and collect the results in an vector.
> >
> >Here attached my code, file, and my question which should be clear now.
> >The
> >question again is instead of using separate loops for each sset1 and
> >sset2,
> >I want one nested loop? Because I have at least 10 subsets
> >(sset1,sset2,sset3…..sset10).
> >
> >Thanks again, EK
> >
> >
> >-------The code------
> >
> >install.packages("data.table")
> >library(data.table)
> >File1 <-  "C:/Users/SampleData.csv"
> >DT <- fread(File1)
> >sset1 <- DT[Num<10&Day<10]
> >sset2 <- DT[Num>10&Day<15]
> >
> ># Count how many combinations of A,B,C,D,E,F in each subset
> >for ( i in 1:length(sset1)){
> >  aa <- c(sset1[Grade=="A",.N],sset1[Grade=="D",.N])
> >  bb <- c(sset1[Grade=="B",.N],sset1[Grade=="F",.N])
> >  cc <- c(sset1[Grade=="C",.N],sset1[Grade=="A",.N])
> >  counts <- c(aa, bb,cc)
> >}
> >
> >for ( i in 1:length(sset2)){
> >  aa1 <- c(sset2[Grade=="A",.N],sset2[Grade=="D",.N])
> >  bb1 <- c(sset2[Grade=="B",.N],sset2[Grade=="F",.N])
> >  cc1 <- c(sset2[Grade=="C",.N],sset2[Grade=="A",.N])
> >  counts <-  c(aa1,bb1,cc1)
> >}
> >
> >-----------The File------------
> >
> >   Num  Color Grade Value    Month Day
> > 1:   1 yellow     A    20      May   1
> > 2:   2  green     B    25     June   2
> > 3:   3  green     A    10    April   3
> > 4:   4  black     A    17   August   3
> > 5:   5    red     C     5 December   5
> > 6:   6 orange     D     0  January  13
> > 7:   7 orange     E    12  January   5
> > 8:   8 orange     F    11 February   8
> > 9:   9 orange     F    99     July  23
> >10:  10 orange     F    70      May   7
> >11:  11  black     A    77     June  11
> >12:  12  green     B    87    April  33
> >13:  13  black     A    79   August   9
> >14:  14  green     A    68 December  14
> >15:  15  black     C    90  January  31
> >16:  16  green     D    79  January  11
> >17:  17  black     E   101 February  17
> >18:  18    red     F    90     July  21
> >19:  19    red     F   112 February  13
> >20:  20    red     F   101     July  20
> >
> >On Tue, May 2, 2017 at 12:35 PM, Ek Esawi <esawiek at gmail.com> wrote:
> >
> >> I have a huge data file; a sample is listed below. I am using the
> >package
> >> data table to process the file and I am stuck on one issue and need
> >some
> >> feedback. I used fread to create a data table. Then I divided the
> >data
> >> table (named File1) into 10 general subsets using common table
> >commands
> >> such as:
> >>
> >>
> >>
> >> AAA <- File1[Num<5&day>15]
> >>
> >> BBB <- File1[Num>15&day<10]
> >>
> >> …..
> >>
> >> …..
> >>
> >> …..
> >>
> >> …..
> >>
> >> …..
> >>
> >> …..
> >>
> >>
> >>
> >> I wanted to divide and count each of the above subsets based on a set
> >of
> >> parameters common to all subsets. I did the following to go through
> >each
> >> subset and it works:
> >>
> >> For (I in 1: length (AAA)) {
> >>
> >>               aa <- c(AAA[color==”green”&grade==”a”,month==”Januray”
> >> .N],[ AAA[color==”green”&grade==”b”& month==”June”’ .N])
> >>
> >> }
> >>
> >>
> >>
> >> The question: I don’t want to have a separate loop for each subset
> >(10
> >> loops). Instead, I was hoping to have 2 nested loops in the form
> >below:
> >>
> >>
> >>
> >> For (I in 1:N)){
> >>
> >>               For (j in 1:M){
> >>
> >>
> >>
> >> }
> >>
> >> }
> >>
> >>
> >>
> >>  Sample
> >>
> >>
> >> Num
> >>
> >> Color
> >>
> >> Grade
> >>
> >> Value
> >>
> >> Month
> >>
> >> Day
> >>
> >> 1
> >>
> >> yellow
> >>
> >> A
> >>
> >> 20
> >>
> >> May
> >>
> >> 1
> >>
> >> 2
> >>
> >> green
> >>
> >> B
> >>
> >> 25
> >>
> >> June
> >>
> >> 2
> >>
> >> 3
> >>
> >> green
> >>
> >> A
> >>
> >> 10
> >>
> >> April
> >>
> >> 3
> >>
> >> 4
> >>
> >> black
> >>
> >> A
> >>
> >> 17
> >>
> >> August
> >>
> >> 3
> >>
> >> 5
> >>
> >> red
> >>
> >> C
> >>
> >> 5
> >>
> >> December
> >>
> >> 5
> >>
> >> 6
> >>
> >> orange
> >>
> >> D
> >>
> >> 0
> >>
> >> January
> >>
> >> 13
> >>
> >> 7
> >>
> >> orange
> >>
> >> E
> >>
> >> 12
> >>
> >> January
> >>
> >> 5
> >>
> >> 8
> >>
> >> orange
> >>
> >> F
> >>
> >> 11
> >>
> >> February
> >>
> >> 8
> >>
> >> 9
> >>
> >> orange
> >>
> >> F
> >>
> >> 99
> >>
> >> July
> >>
> >> 23
> >>
> >> 10
> >>
> >> orange
> >>
> >> F
> >>
> >> 70
> >>
> >> May
> >>
> >> 7
> >>
> >> 11
> >>
> >> black
> >>
> >> A
> >>
> >> 77
> >>
> >> June
> >>
> >> 11
> >>
> >> 12
> >>
> >> green
> >>
> >> B
> >>
> >> 87
> >>
> >> April
> >>
> >> 33
> >>
> >> 13
> >>
> >> black
> >>
> >> A
> >>
> >> 79
> >>
> >> August
> >>
> >> 9
> >>
> >> 14
> >>
> >> green
> >>
> >> A
> >>
> >> 68
> >>
> >> December
> >>
> >> 14
> >>
> >> 15
> >>
> >> black
> >>
> >> C
> >>
> >> 90
> >>
> >> January
> >>
> >> 31
> >>
> >> 16
> >>
> >> green
> >>
> >> D
> >>
> >> 79
> >>
> >> January
> >>
> >> 11
> >>
> >> 17
> >>
> >> black
> >>
> >> E
> >>
> >> 101
> >>
> >> February
> >>
> >> 17
> >>
> >> 18
> >>
> >> red
> >>
> >> F
> >>
> >> 90
> >>
> >> July
> >>
> >> 21
> >>
> >> 19
> >>
> >> red
> >>
> >> F
> >>
> >> 112
> >>
> >> February
> >>
> >> 13
> >>
> >> 20
> >>
> >> red
> >>
> >> F
> >>
> >> 101
> >>
> >> July
> >>
> >> 20
> >>
> >>
> >>
> >
> >       [[alternative HTML version deleted]]
> >
> >______________________________________________
> >R-help at 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.
>

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