Hi Alan,
You can avoid the if() else() you're using in your function by replacing it
with the recode() function in the car package. I'm pretty sure it will speed
up your function.

See ?recode after loading the car package:

require(car)
?recode

HTH,

Jorge


On Wed, Apr 22, 2009 at 2:56 PM, Alan Cohen <CohenA@smh.toronto.on.ca>wrote:

> Hi R users,
>
> I am trying to assign ages to age classes for a large data set (123,000
> records), and using a for-loop was too slow, so I wrote a function and used
> apply.  However, the function does not properly assign the first two classes
> (the rest are fine).  It appears that when age is one digit, it does not get
> assigned properly.
>
> I tried to provide a small-scale work-up (at the end of the email) but it
> does not reproduce the problem; the best I can do is to provide my code and
> the output below.  As you can see, I've confirmed that age is numeric, that
> all values are integers, and that pieces of the code work independently.
>  Any thoughts would be appreciated.
>
> To add to the mystery, depending which rows of my data set I select, I get
> different problems.  mds[1:100,] gives the problem above, as do
> mds[100:200,] , mds[150:250,] and mds[10000:10100,].  However, with
> mds[200:300,], mds[250:350,] and mds[1000:1100,], only ages with 3 digits
> are correctly assigned - all ages <100 are returned as NA.
>
> I'm using R v 2.8.1 on Windows XP.
>
> Cheers,
> Alan Cohen
> Centre for Global Health Research,
> Toronto,ON
>
> > ageassign <- function(x){
> +   y <- NA
> +   if (x[11] %in% c(0:4)) {y <- "0-4"}
> +   else if (x[11] %in% c(5:14)) {y <- "5-14" }
> +   else if (x[11] %in% c(15:29)) {y <- "15-29" }
> +   else if (x[11] %in% c(30:69)) {y <- "30-69"}
> +   else if (x[11] %in% c(70:79)) {y <- "70-79"}
> +   else if (x[11] %in% c(80:125)) {y <- "80+"}
> +   return(y)
> + }
> > jj <- apply(mds[1:100,],1,FUN=ageassign)
> > jj
>      1       2       3       4       5       6       7       8       9
>  10      11      12      13
>     NA   "80+" "30-69" "30-69"   "80+"      NA "30-69" "30-69" "70-79"
> "15-29" "15-29" "30-69" "70-79"
>     14      15      16      17      18      19      20      21      22
>  23      24      25      26
>  "80+"      NA "30-69" "30-69" "30-69"   "80+"   "80+" "15-29" "70-79"
> "30-69" "70-79" "70-79" "30-69"
>     27      28      29      30      31      32      33      34      35
>  36      37      38      39
> "70-79"   "80+"      NA   "80+" "70-79"      NA "15-29" "15-29"      NA
>  NA "70-79" "30-69" "30-69"
>     40      41      42      43      44      45      46      47      48
>  49      50      51      52
> "70-79" "30-69" "30-69" "30-69" "70-79" "30-69" "30-69" "70-79" "15-29"
> "30-69"      NA "15-29" "30-69"
>     53      54      55      56      57      58      59      60      61
>  62      63      64      65
> "30-69"      NA "70-79" "30-69" "30-69" "30-69" "30-69" "15-29" "30-69"
> "30-69" "70-79" "30-69"      NA
>     66      67      68      69      70      71      72      73      74
>  75      76      77      78
> "30-69" "30-69" "30-69" "30-69" "30-69"   "80+" "30-69"   "80+" "70-79"
> "30-69" "30-69" "30-69"      NA
>     79      80      81      82      83      84      85      86      87
>  88      89      90      91
> "30-69" "30-69" "30-69"      NA   "80+" "30-69" "30-69" "30-69"      NA
> "15-29" "30-69" "30-69" "30-69"
>     92      93      94      95      96      97      98      99     100
> "30-69" "30-69" "30-69" "30-69" "70-79" "30-69" "30-69" "30-69" "30-69"
> > mds[1:100,11]
>  [1]  3 82 40 35 82  1 37 57 71 22 21 52 73 86  1 43 60 63 84 88 29 73 69
> 75 73 43 75 83  4 83 77  1 27
>  [34] 15  1  6 76 51 45 71 54 64 69 70 48 38 74 26 37  4 18 63 59  8 78 63
> 67 62 50 21 66 69 75 57  4 50
>  [67] 58 60 61 62 83 69 92 75 30 49 69  1 69 63 69  0 93 64 59 69  2 25 32
> 60 66 67 54 53 64 79 59 49 59
> [100] 64
> > table(mds[,11])
>
>   0    1    2    3    4    5    6    7    8    9   10   11   12   13   14
> 15   16   17   18   19
> 3123 6441 3856 2884 1968 1615 1386 1088 1098  721  943  681  511  380  426
>  835  571  555  719  653
>  20   21   22   23   24   25   26   27   28   29   30   31   32   33   34
> 35   36   37   38   39
>  879  715  672  631  655  773  680  713  769  538  685  566  729  702  652
>  766  683  723  821  675
>  40   41   42   43   44   45   46   47   48   49   50   51   52   53   54
> 55   56   57   58   59
>  774  650  908  892  784  925  781 1043 1161  924 1087  827 1261 1356 1297
> 1272 1277 1614 1831 1523
>  60   61   62   63   64   65   66   67   68   69   70   71   72   73   74
> 75   76   77   78   79
> 1702 1251 1954 2157 1901 2090 1874 2705 3085 2529 2488 1777 2701 2586 2308
> 2020 1801 2269 2486 1856
>  80   81   82   83   84   85   86   87   88   89   90   91   92   93   94
> 95   96   97   98   99
> 1762 1047 1413 1326  967 1013  753  870  884  531  601  277  364  301  193
>  288  149  174  169  470
>  100  101  102  103  104  105  106  107  108  114  115  117  118  120  125
>  15    2    5    7    2    4    1    1    2    1    1    2    2    2    1
> > mode(mds[,11])
> [1] "numeric"
>
> > mds[1,11] %in% c(0:4)
> [1] TRUE
> > if (mds[1,11] %in% c(0:4)) {y <- "0-4"}
> > y
> [1] "0-4"
>
> > xx <- matrix(trunc(runif(30,0,125)),15,2)
> > aassign <- function(x){
> +   y <- NA
> +   if (x[2] %in% c(0:4)) {y <- "0-4"}
> +   else if (x[2] %in% c(5:14)) {y <- "5-14" }
> +   else if (x[2] %in% c(15:29)) {y <- "15-29" }
> +   else if (x[2] %in% c(30:69)) {y <- "30-69"}
> +   else if (x[2] %in% c(70:79)) {y <- "70-79"}
> +   else if (x[2] %in% c(80:125)) {y <- "80+"}
> +   return(y)
> + }
> > jj <- apply(xx,1,FUN=aassign)
> > t(xx)
>     [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11] [,12] [,13]
> [,14] [,15]
> [1,]   23   98  107   94   76  103  106   40   66    11   109   101    96
>  37    18
> [2,]   11   57   58   91   43  123  103   77    4    79    64    10     8
> 105    76
> > jj
>  [1] "5-14"  "30-69" "30-69" "80+"   "30-69" "80+"   "80+"   "70-79" "0-4"
>   "70-79" "30-69" "5-14"
> [13] "5-14"  "80+"   "70-79"
> >
>
> ______________________________________________
> R-help@r-project.org mailing list
> 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.
>

	[[alternative HTML version deleted]]


