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a weird "cut" question

3 messages · Erin Hodgess, William Dunlap, Jeff Newmiller

Erin Hodgess
# 
Dear R People:

I have the following data:
[1] 47677 47602 47678 47905 47909 47906 47605 47673 47607
[1] (4.76e+04,4.77e+04] (4.76e+04,4.77e+04] (4.76e+04,4.77e+04]
[4] (4.78e+04,4.79e+04] (4.78e+04,4.79e+04] (4.78e+04,4.79e+04]
[7] (4.76e+04,4.77e+04] (4.76e+04,4.77e+04] (4.76e+04,4.77e+04]
Levels: (4.76e+04,4.77e+04] (4.77e+04,4.78e+04] (4.78e+04,4.79e+04]
so I have cut ail.df[,1] into 3 levels.  However, the second level
never appears in the data set.

Is there a way to set cut such that every level appears, please?

thanks in advance,
Sincerely,
Erin
William Dunlap
# 
You could use quantile() to create the breakpoints
  > x <- c(47677, 47602, 47678, 47905, 47909, 47906, 47605, 47673, 47607)
  > cutX <- cut(x, breaks=quantile(x, (0:3)/3), include.lowest=TRUE)
  > cutX
  [1] (4.77e+04,4.78e+04] [4.76e+04,4.77e+04] (4.77e+04,4.78e+04] (4.78e+04,4.79e+04]
  [5] (4.78e+04,4.79e+04] (4.78e+04,4.79e+04] [4.76e+04,4.77e+04] (4.77e+04,4.78e+04]
  [9] [4.76e+04,4.77e+04]
  Levels: [4.76e+04,4.77e+04] (4.77e+04,4.78e+04] (4.78e+04,4.79e+04]
  > table(cutX)
  cutX
  [4.76e+04,4.77e+04] (4.77e+04,4.78e+04] (4.78e+04,4.79e+04] 
                  3                   3                   3

This will fail if there are only 2 distinct values in the dataset.

Bill Dunlap
Spotfire, TIBCO Software
wdunlap tibco.com
Jeff Newmiller
# 
You picked a data set and ask whether the function parameters can fix the partition. Perhaps you should consider a different data set: rep(47677,9). I think you cannot "fix" the partition without considering the data also. Given that, you may be able to go back and manually identify a partition that works with a particular data set (e.g. use quantiles), but you may be asking too much to automate that for all data sets.
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Sent from my phone. Please excuse my brevity.
Erin Hodgess <erinm.hodgess at gmail.com> wrote: