[R] stumped on how to reorder factors

[David Winsemius]

On Aug 30, 2011, at 10:00 PM, Markus Weisner wrote:

> snipped long preamble:

>  Now I have a more complicated
> problem and I need help.  Assuming the following factor:
>
>
> B = as.factor(c("Engine 1", "Engine 10", "Ladder 3", "Engine 3",  
> "Ladder 10",
> "Engine 10"))
>
> levels(B)
>
>
> I would like the factor ordered first by the proceeding unit type  
> and then
> ordered by the following integer.  In this case, I would like to see  
> this
> order:  Engine 1, Engine 3, Engine 10, Ladder 3, Ladder 10.  I have  
> tried
> many different ways of separating out the unit type from the number,  
> but am
> having trouble figuring out a good way of achieving this factor  
> order.  For
> such a small example, I could obviously manually change the order,  
> but I am
> dealing with much larger datasets with many unit types and up to 20
> different numbers for each unit type.  Having an automated way of  
> ordering
> these units would be a huge help.  Thanks in advance for any help  
> you can
> provide.
>

library(gtools)
?mixedsort


> --Markus Weisner
>
> 	[[alternative HTML version deleted]]
>
-- 

David Winsemius, MD
West Hartford, CT