[R] beginner programming question

[Tony Plate]

Another way to approach this is to first massage the data into a more 
regular format.  This may or may not be simpler or faster than other 
solutions suggested.

 > x <- read.table("clipboard", header=T)
 > x
   rel1 rel2 rel3 age0 age1 age2 age3 sex0 sex1 sex2 sex3
1    1    3   NA   25   23    2   NA    1    2    1   NA
2    4    1    3   35   67   34   10    2    2    1    2
3    1    4    4   39   40   59   60    1    2    2    1
4    4   NA   NA   45   70   NA   NA    2    2   NA   NA
 > nn <- c("rel","age0","age","sex0","sex")
 > xx <- rbind("colnames<-"(x[,c("rel1","age0","age1","sex0","sex1")], nn),
+  "colnames<-"(x[,c("rel2","age0","age2","sex0","sex2")], nn),
+  "colnames<-"(x[,c("rel3","age0","age3","sex0","sex3")], nn))
 > xx
    rel age0 age sex0 sex
1    1   25  23    1   2
2    4   35  67    2   2
3    1   39  40    1   2
4    4   45  70    2   2
11   3   25   2    1   1
21   1   35  34    2   1
31   4   39  59    1   2
41  NA   45  NA    2  NA
12  NA   25  NA    1  NA
22   3   35  10    2   2
32   4   39  60    1   1
42  NA   45  NA    2  NA
 >
 > rbind(subset(xx, xx$rel==1 & (xx$sex0==1 | 
xx$sex0==xx$sex))[,c("age0","age")], subset(xx, xx$rel==1 & xx$sex==1 & 
xx$sex0!=xx$sex)[,c("age","age0")])
    age0 age
1    25  23
3    39  40
21   35  34
 >

hope this helps,

Tony Plate

PS.  To advanced R users: Is the above usage of the "colnames<-" function 
within an expression regarded as acceptable or as undesirable programming 
style? -- I've rarely seen it used, but it can be quite useful.

At Wednesday 09:28 PM 12/17/2003 +0200, Adrian Dusa wrote:
>Hi all,
>
>
>
>The last e-mails about beginners gave me the courage to post a question;
>from a beginner's perspective, there are a lot of questions that I'm
>tempted to ask. But I'm trying to find the answers either in the
>documentation, either in the about 15 free books I have, either in the
>help archives (I often found many similar questions posted in the past).
>
>Being an (still actual) user of SPSS, I'd like to be able to do
>everything in R. I've learned that the best way of doing it is to
>struggle and find a solution no matter what, refraining from doing it
>with SPSS. I've became more and more aware of the almost unlimited
>possibilities that R offers and I'd like to completely switch to R
>whenever I think I'm ready.
>
>
>
>I have a (rather theoretical) programming problem for which I have found
>a solution, but I feel it is a rather poor one. I wonder if there's some
>other (more clever) solution, using (maybe?) vectorization or
>subscripting.
>
>
>
>A toy example would be:
>
>
>
>rel1       rel2       rel3       age0     age1     age2     age3
>sex0     sex1     sex2     sex3
>
>1          3          NA        25         23         2          NA
>1          2          1          NA
>
>4          1          3          35         67         34         10
>2          2          1          2
>
>1          4          4          39         40         59         60
>1          2          2          1
>
>4          NA        NA        45         70         NA        NA
>2          2          NA        NA
>
>
>
>where rel1...3 states the kinship with the respondent (person 0)
>
>code 1 meaning husband/wife, code 4 meaning parent and code 3 for
>children.
>
>
>
>I would like to get the age for husbands (code 1) in a first column and
>wife's age in the second:
>
>
>
>ageh     agew
>
>25         23
>
>34         35
>
>39         40
>
>
>
>My solution uses *for* loops and *if*s checking for code 1 in each
>element in the first 3 columns, then checking in the last three columns
>for husband's code, then taking the corresponding age in a new matrix.
>I've learned that *for* loops are very slow (and indeed with my dataset
>of some 2000 rows and 13 columns for kinship it takes quite a lot).
>
>I found the "Looping" chapter in "S poetry" very useful (it did saved me
>from *for* loops a couple of times, thanks!).
>
>
>
>Any hints would be appreciated,
>
>Adrian
>
>
>
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>Adrian Dusa (adi at roda.ro)
>Romanian Social Data Archive (www.roda.ro <http://www.roda.ro/> )
>1, Schitu Magureanu Bd.
>76625 Bucharest sector 5
>Romania
>
>
>Tel./Fax:
>
>+40 (21) 312.66.18\
>
>+40 (21) 312.02.10/ int.101
>
>
>
>
>         [[alternative HTML version deleted]]
>
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