# [R] Loop

jim holtman jholtman at gmail.com
Thu Nov 4 21:58:54 CET 2010

```Is this closer to what you want, assuming that it is the value of the
most frequently occurring:

> apply(mat, 2, function(x) head(names(sort(table(x), decreasing=T)),5))
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
[1,] "1"  "14" "5"  "1"  "4"  "14" "6"  "18" "11" "19"
[2,] "3"  "3"  "13" "12" "3"  "11" "14" "9"  "18" "12"
[3,] "2"  "18" "20" "8"  "11" "12" "17" "14" "14" "7"
[4,] "5"  "11" "8"  "19" "5"  "18" "18" "15" "16" "10"
[5,] "18" "13" "11" "11" "17" "3"  "4"  "16" "8"  "16"
>

2010/11/4 Matevž Pavlič <matevz.pavlic at gi-zrmk.si>:
> Hi again,
>
> Stil don't qute get it...
>
> Here's what i did :
>
>
> With that i get a table(list/matrix...) which gives the highest count of occurances of each value in a table (at least i think so)
> But the problem is because it does not tell which value occurs the most (has the highest count).
>
> If written like this :
>>apply(mat, 2, function(x) sort(table(x),decreasing=T))
>
>
> I get decreasingly sorted values of counts of occurances of a specific field and the value of that field for each column:
>
>
> \$W2
> x
>         PEŠČEN       GRADUIRAN              IN            PROD              DO         GLINAST           PROD,        PREPEREL         MELJAST           GRUŠČ           GLINA               Z            MALO     GRANULIRANA
>           1872            1542             552             519             458             214             175             174             132             114              62              53              47              45
>           ZELO         PEŠČENA       ZAGLINJEN      KARBONATNI      SKRILAVCA,               S       SKRILAVCA      GRANULIRAN          PEČŠEN           VEZAN        ZAOBLJEN             GR.          DROBEN           SLABO
>             40              34              31              26              26              25              25              24              17              17              17              15              12              12
>         GRUŠČ,        MELJASTO          PEŠEEN           DOBRO           GRAN.      PEŠČENJAKA     HUDOURNIŠKI          MELJNA           PEŠČN      GIRADUIRAN        GLINAST,            GOST       GRADUTRAN         GRANUL.
>             11              11              11              10              10               9               8               8               8               6               6               6               6               6
>              6               6               5               5               5               4               4               4               4               4               4               3               3               3
>       MELJAST,           PEČEN         PEŠČEN,          PLASTI                           DELNO          GLINA,        GLINASTO        GRADUIAN       GRADULRAN        GRDUIRAN          GRUŠČ.           KARB.     KONGLOMERAT
>              3               3               3               3               2               2               2               2               2               2               2               2               2               2
>   KONGLOMERAT,            MELJ        NEKOLIKO            OKER          PESEK,         PEŠČCEN         PEŠČEN.         PLASTEH             POD        PPEPEREL            RPOD          UMAZAN       ZAOBLJEN,               -
>              2               2               2               2               2               2               2               2               2               2               2               2               2               1
>
>
> But the first code somhove looses the acutal value of the field and just gives the count
>
> VrtinaID ZapStev GlobinaOd GlobinaDo USCS Opis   W1   W2   W3   W4   W5   W6   W7  W8  W9  W10  W11  W12  W13  W14  W15
>  [1,]       15    1248       282       290 2131   15 1820 1872 1677 1479 1441 1465 1261 769 848 1088 1490 1968 2459 2943 3408
>  [2,]       11    1119       198       235 1305   13 1791 1542 1495 1334 1317 1247  829 652 783  660  606  603  381  381  301
>  [3,]       11    1078       174       210  784   11  532  552  566  529  532  716  511 575 576  416  464  384  368  282  279
>  [4,]       11     835       147       173  691   11  471  519  390  351  358  571  364 521 556  381  398  352  287  282  259
>  [5,]       10     584       133       172  646   11  376  458  296  311  323  195  252 329 429  343  397  336  244  242  224
>  [6,]       10     389       123       142  386   10  253  214  237  268  310  130  233 265 376  263  378  258  228  210  205
>  [7,]       10     257       114       130  183   10  247  175  201  242  157  130  179 258 267  219  230  239  197  185  155
>  [8,]        9     198       105       126  148    9  135  174  157  170  146  102  163 213 266  215  221  188  197  179  155
>  [9,]        9     171       101        95   71    9  102  132  139  161  141   89  145 199 140  192  205  168  191  160  122
> [10,]        9     144        94        91   31    8   93  114  124  158  121   84  136 183 134  185  160  158  181  155  115
>
>
> How would i get the count and the actual value of the field in the same table so that it would look something like this :
> VrtinaID.count VrtinaID.value    ZapStev.count ZapStev.value
>  [1,]       15          V-1     1248      ena  ...
> [2,]       11           V-12    1119      dva  ...
> .
> .
> .
>
> Hope that explains it and thanks for help,
>
>  m
>
> .
> str(w)
>
> -----Original Message-----
> From: Petr PIKAL [mailto:petr.pikal at precheza.cz]
> Sent: Thursday, November 04, 2010 4:56 PM
> To: Matevž Pavlič
> Cc: r-help at r-project.org
> Subject: Re: [R] Loop
>
> Hi
>
> r-help-bounces at r-project.org napsal dne 04.11.2010 15:49:31:
>
>> Hi all,
>>
>> I understand that you most of you this is a peice of cake but i am a
> complete
>> newbie in this....so any example would be greatly aprpeciated and also
> any
>> hint as how to get around in R. Frankly i sometimes see the help files
> kinda confusing.
>
>> > >> w1<-table(lit\$W1)
>> > >> w1<-as.data.frame(w1)
>> > >> write.table(w1,file="w1.csv",sep=";",row.names=T, dec=".")
>> > >> w1<- w1[order(w1\$Freq, decreasing=TRUE),] w1<-head(w1, 20)
>
> Suppose you have data frame or matrix, and you want to have 5 most common
> values from each column
>
> # prepare matrix
> x<-sample(1:20, 1000000, replace=T)
> mat<-matrix(x, ncol=10)
>
> #apply user defined function for each column
> apply(mat, 2, function(x) head(sort(table(x), decreasing=T),5))
>     [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
> [1,] 5091 5135 5174 5133 5199 5097 5165 5157 5134  5068
> [2,] 5073 5111 5143 5064 5113 5078 5102 5157 5131  5065
> [3,] 5058 5092 5115 5051 5079 5064 5088 5128 5076  5063
> [4,] 5056 5073 5114 5047 5059 5044 5037 5064 5071  5063
> [5,] 5047 5064 5072 5041 5057 5041 5035 5058 5032  5061
>
> If you want to do it in loop (can be quicker sometimes) and save it to
> list make a list
>
> lll<-vector("list", 10)
>
> and fill it with your results
>
> for (i in 1:10) lll[[i]]<-head(sort(table(mat[,i]), decreasing=T),5)
>
> and now you can call values from this lll list simply by
>
> lll[5]
> [[1]]
>
>   9   15   13    6   16
> 5199 5113 5079 5059 5057
>
> lll[[5]]
>
>   9   15   13    6   16
> 5199 5113 5079 5059 5057
>
> or even
>
> lll[[5]][3]
>  13
> 5079
>
> without need for writing to individual files pasting together letters and
> numbers etc.
>
> There shall be R-intro document in your installation and it is worth
> reading. It is not so big, you can manage it in less then month if you
> complete more than 3 pages per day.
>
> Regards
> Petr
>
>
>
>>
>> M
>>
>> -----Original Message-----
>> From: Petr PIKAL [mailto:petr.pikal at precheza.cz]
>> Sent: Thursday, November 04, 2010 3:40 PM
>> To: Matevž Pavlič
>> Cc: r-help at r-project.org
>> Subject: Re: [R] Loop
>>
>> Hi
>>
>> r-help-bounces at r-project.org napsal dne 04.11.2010 14:21:38:
>>
>> > Hi David,
>> >
>> > I am still having troubles with that loop ...
>> >
>> > This code gives me (kinda) the name of the column/field in a data
> frame.
>> Filed
>> > names are form W1-W10. But there is a space between W and a number -->
>> "W 10",
>> > and column (field) names do not contain numbers.
>> >
>> > >for(i in 1:10)
>> > >{
>> > >vari <- paste("W",i)
>> > >}
>> > >vari
>> >
>> > [1] "W 10"
>> >
>> > Now as i understand than i would call different columns to R with
>> >
>> > >w<-lit[[vari]]
>> >
>> > Or am i wrong again?
>> >
>> > Then I would probably need another loop to create the names of the
>> variables
>> > on R, i.e. w1 to w10. Is that a general idea for the procedure?
>>
> files/objects
>> constructed by some paste(whatever, i) solution you can save results in
> list
>> or data.frame or matrix and simply use basic subsetting procedures or
> lapply/
>> sapply functions.
>>
>> I must say I never used such paste(...) construction yet and I work with
> R for
>> quite a long time.
>>
>> Regards
>> Petr
>>
>>
>> >
>> >
>> > Thank for the help, m
>> >
>> > -----Original Message-----
>> > From: David Winsemius [mailto:dwinsemius at comcast.net]
>> > Sent: Wednesday, November 03, 2010 10:41 PM
>> > To: Matevž Pavlič
>> > Cc: r-help at r-project.org
>> > Subject: Re: [R] Loop
>> >
>> >
>> > On Nov 3, 2010, at 5:03 PM, Matevž Pavlič wrote:
>> >
>> > > Hi,
>> > >
>> > > Thanks for the help and the manuals. Will come very handy i am sure.
>> > >
>> > > But regarding the code i don't hink this is what i want....basically
>
>> > > i
>>
>> > > would like to repeat bellow code :
>> > >
>> > > w1<-table(lit\$W1)
>> > > w1<-as.data.frame(w1)
>> >
>> > It appears you are not reading for meaning. Burns has advised you how
>> > to
>>
>> > construct column names and use them in your initial steps. The `\$`
>> function is
>> > quite limited in comparison to `[[` , so he was showing you a method
>> that
>> > would be more effective.  BTW the as.data.frame step is unnecessary,
>> since the
>> > first thing write.table does is coerce an object to a data.frame. The
>> > "write.table" name is misleading. It should be "write.data.frame". You
>> cannot
>> > really write tables with write.table.
>> >
>> > You would also use:
>> >
>> >   file=paste(vari, "csv", sep=".") as the file argument to write.table
>> >
>> > > write.table(w1,file="w1.csv",sep=";",row.names=T, dec=".")
>> >
>> > What are these next actions supposed to do after the file is written?
>> > Are you trying to store a group of related "w" objects that will later
>> be
>> > indexed in sequence? If so, then a list would make more sense.
>> >
>> > --
>> > David.
>> >
>> > > w1<- w1[order(w1\$Freq, decreasing=TRUE),] w1<-head(w1, 20)
>> > >
>> > > 20 times, where W1-20 (capital letters) are the fields in a
>> > > data.frame
>>
>> > > called "lit" and w1-20 are the data.frames being created.
>> > >
>> > > Hope that explains it better,
>> >
>> > > m
>> > >
>> > > -----Original Message-----
>> > > From: Patrick Burns [mailto:pburns at pburns.seanet.com]
>> > > Subject: Re: [R] Loop
>> > >
>> > > If I understand properly, you'll want something like:
>> > >
>> > > lit[["w2"]]
>> > >
>> > >
>> > > lit\$w2
>> > >
>> > > more accurately:
>> > >
>> > > for(i in 1:20) {
>> > > vari <- paste("w", i)
>> > > lit[[vari]]
>> > >
>> > > ...
>> > > }
>> > >
>> > > The two documents mentioned in my
>> > >
>> > > On 03/11/2010 20:23, Matevž Pavlič wrote:
>> > >> Hi all,
>> > >>
>> > >> I managed to do what i want (with the great help of thi mailing
>> > >> list)  manually . Now i would like to automate it. I would probably
>
>> > >> need a for loop for to help me with this...but of course  I have no
>
>> > >> idea how to do that in R.  Bellow is the code that i would like to
>> > >> be
>>
>> > >> replicated for a number of times (let say 20). I would like to
>> > >> achieve  that w1 would change to w2, w3, w4 ... up to w20 and by
>> > >> that
>>
>> > >> create 20 data.frames that I would than bind together with cbind.
>> > >>
>> > >> (i did it like shown bellow -manually)
>> > >>
>> > >> w1<-table(lit\$W1)
>> > >> w1<-as.data.frame(w1)
>> > >> write.table(w1,file="w1.csv",sep=";",row.names=T, dec=".")
>> > >> w1<- w1[order(w1\$Freq, decreasing=TRUE),] w1<-head(w1, 20)
>> > >>
>> > >> w2<-table(lit\$W2)
>> > >>
>> > >> w2<-as.data.frame(w2)
>> > >>
>> > >> write.table(w2,file="w2.csv",sep=";",row.names=T, dec=".")
>> > >>
>> > >> w2<- w2[order(w2\$Freq, decreasing=TRUE),]
>> > >>
>> > >> .
>> > >> .
>> > >> .
>> > >>
>> > >> Thanks for the help,m
>> >
>> > >
>> >
>> > David Winsemius, MD
>> > West Hartford, CT
>> >
>> > ______________________________________________
>> > R-help at r-project.org mailing list
>> > https://stat.ethz.ch/mailman/listinfo/r-help
>> http://www.R-project.org/posting-guide.html
>> > and provide commented, minimal, self-contained, reproducible code.
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> and provide commented, minimal, self-contained, reproducible code.
>

--
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?

```