[R] histogram of dates
marc_schwartz at me.com
Fri Apr 22 19:49:38 CEST 2011
On Apr 22, 2011, at 12:31 PM, Terry Therneau wrote:
> I can't seem to get a histogram of dates:
> tmt910% R --vanilla
> R version 2.13.0 (2011-04-13)
> Copyright (C) 2011 The R Foundation for Statistical Computing
> ISBN 3-900051-07-0
>> temp <- as.Date(1:200, origin="1970/01/01")
>  "1970-01-02" "1970-07-20"
> Error in .Internal(inherits(x, what, which)) : 'x' is missing
> 3: inherits(breaks, "Date")
> 2: hist.Date(temp)
> 1: hist(temp)
> Existence of hist.Date implies that this is intended to work.
> The MASS version fails in a different way.
> Error in Ops.difftime(n, 2) : '%/%' not defined for "difftime" objects
temp <- as.Date(1:200, origin="1970/01/01")
hist(temp, breaks = "months")
There is no default for the 'breaks' argument in hist.Date() and there does not appear to be a check for a missing value for this argument.
truehist() does not have a method for Date class objects, but you could do:
or perhaps use cut.Date() on the vector and create the intervals/breakpoints that you wish to use.
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