[R] Re-ordering factors

[Peter Dalgaard]

James Reilly wrote:
> Using reorder.factor from the stats package seems to work:
>
> educ$ed <- reorder(educ$Education, sort(rep(1:4,5)))
> levels(educ$Education)
> [1] "CompletedHS"  "IncompleteHS" "Uni1-3"       "Uni4+"
> levels(educ$ed)
> [1] "IncompleteHS" "CompletedHS"  "Uni1-3"       "Uni4+" 
> xtabs(Count ~ ed + Age_Group, data=educ)
>                Age_Group
> ed             25-34 35-44 45-54 55-64   >64
>    IncompleteHS  5416  5030  5777  7606 13746
>    CompletedHS  16431  1855  9435  8795  7558
>    Uni1-3        8555  5576  3124  2524  2503
>    Uni4+         9771  7596  3904  3109  2483
>   
Notice that factor() itself will do it quite happily:

ed <- factor(Education, levels = c("IncompleteHS", "CompletedHS", "Uni1-3", "Uni4+"))

or even, utilizing the fact that the levels were in the right order to begin with

> educ$Education <- factor(educ$Education, levels=unique(educ$Education))
> educ$Age_Group <- factor(educ$Age_Group, levels=unique(educ$Age_Group))
> xtabs(Count ~ Education + Age_Group, data=educ)
              Age_Group
Education      25-34 35-44 45-54 55-64   >64
  IncompleteHS  5416  5030  5777  7606 13746
  CompletedHS  16431  1855  9435  8795  7558
  Uni1-3        8555  5576  3124  2524  2503
  Uni4+         9771  7596  3904  3109  2483





-- 
   O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
  c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
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