>>>>> "Gad" == Gad Abraham <[EMAIL PROTECTED]>
>>>>> on Tue, 20 Mar 2007 17:02:18 +1100 writes:
Gad> Hi,
Gad> Is this a bug in truehist()?
>> library(MASS)
>> x <- rep(1, 10)
>> truehist(x)
Gad> Error in pretty(data, nbins) : invalid 'n' value
You get something similar though slightly more helpful
from
hist(x, "scott")
which then uses the same method for determining the number of bins /
classes for the histogram.
I'd say the main "bug" is in
nclass.scott() [ and also nclass.FD() ]
which do not work when var(x) == 0 as in this case.
One could argue that
1) truehist(x) should not use "scott" as
default when var(x) == 0 {hence a buglet in truehist()}
and either
2) both hist() and truehist() should produce a better error
message when "scott" (or "FD") is used explicitly and var(x) == 0
or, rather IMO,
3) nclass.scott(x) and nclass.FD(x) should be extended to return a
non-negative integer even when var(x) == 0
Martin Maechler, ETH Zurich
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