[R] Hist with Dates

[Jeff Newmiller]

You should read the help for hist carefully:

?hist.Date

hist has very specific rules for applying breaks that are often different than tabulation (tapply or aggregate, with or without using the cut function first).
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Sent from my phone. Please excuse my brevity.

Dominic Roye <dominic.roye at gmail.com> wrote:

>Hello R-Helpers,
>
>
>I would like to generate the frequencies of dates (data.RData).
>
>str(data)
>Date[1:43748], format: "2001-01-01" "2001-01-01" "2001-01-01"
>"2001-01-01"
>...
>
>
>test <- hist(data,"days",freq=T)
>> test$counts
>[1] 27 17 12 15  6  4  5 13  5 13 15  9  7 10 11 21 10 10  9 11 15  7
>10
>14
>
>
>but the count is wrong, because i have only 9 times 01/01/2001 etc.
>
>> data[1:30]
> [1] "2001-01-01" "2001-01-01" "2001-01-01" "2001-01-01" "2001-01-01"
> [6] "2001-01-01" "2001-01-01" "2001-01-01" "2001-01-01"
>
>"2001-01-02"
>[11] "2001-01-02" "2001-01-02" "2001-01-02" "2001-01-02" "2001-01-02"
>[16] "2001-01-02" "2001-01-02" "2001-01-02" "2001-01-02" "2001-01-02"
>[21] "2001-01-03" "2001-01-03" "2001-01-03" "2001-01-03" "2001-01-03"
>[26] "2001-01-03" "2001-01-03" "2001-01-03" "2001-01-03" "2001-01-03"
>
>
>
>Now, when i give R the breaks.
>
>> br <-
>seq(as.Date("31.12.2000",format="%d.%m.%Y"),as.Date("01.01.2012",format="%d.%m.%Y"),by=1)
>> test2<- hist(data,br,freq=T)
>> test2$counts[1:10]
> [1] 12 15 17 12 15  6  4  5 13  5
>
>
>In this case, neither get the right counts but limiting i get the
>correct
>counts:
>
>> test3<- hist(data[1:50],br[1:6],freq=T)
>> test3$counts
>[1]  9 11 13  9  8
>
>
>I hope someone can help me with this problem.
>
>
>Thank you very much!!
>
>Best regards,
>
>Dominic
>
>
>------------------------------------------------------------------------
>
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