Re: [R] Time data
On 12/20/05, Marc Bernard <[EMAIL PROTECTED]> wrote:
> Dear All, I wonder how to compute the age from the date of birth and the date
> of examination. Suppose that have the following data:
>
> df <- as.data.frame(rbind(c(1,"10/08/1950","15/03/1998"),
> c(1,"10/08/1950","20/07/1998"), c(1,"10/08/1950","23/10/1998")))
>
> names(df) <- c("ID", "date_birth", "date_exam")
>
> where:
> date_birth: is the date of birth
> date_exam: date of examination
>
> I used the following program to compute the value of the age :
>
First ensure that df stores its dates using "Date" class in the first
place. If your data is stored in the correct representation then
everything becomes easier subsequently:
fmt <- "%d/%m/%Y"
df[,2] <- as.Date(df[,2], fmt)
df[,3] <- as.Date(df[,3], fmt)
# converting them to numeric gives the number of days since
# the Epoch and one can just subtact those:
(as.numeric(df$date_exam) - as..numeric(df$date_birth)) / 365
R News 4/1 Help Desk article has more info on dates.
> difftime(strptime(as.character(df$date_exam), '%d/%m/%Y'),
> strptime(as.character(df$date_birth), '%d/%m/%Y'))/365.25
>
> which gives me as an output:
>
> > Time differences of 47.59491, 47.94251, 48.20260 days
>
> theses values are actually the 3 ages (but
>
> My questions are:
>
> 1- Why in the output it says "days" instead of "years")
>
> 2- How can I obtain the output as a numeric vector, without the statement
> "Time difference of ". This is in order to use it in my calculations.
>
> 3- Is there a way quicker and less redondant to compute the age form the
> date_birth and date_exam?
>
> Thanks a lot,
>
> Bernard,
>
>
>
> -
>
>[[alternative HTML version deleted]]
>
> __
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> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
>
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Re: [R] Time data
Hi
On 20 Dec 2005 at 11:12, Marc Bernard wrote:
Date sent: Tue, 20 Dec 2005 11:12:28 +0100 (CET)
From: Marc Bernard <[EMAIL PROTECTED]>
To: r-help@stat.math.ethz.ch
Subject: [R] Time data
> Dear All, I wonder how to compute the age from the date of birth and
> the date of examination. Suppose that have the following data:
>
> df <- as.data.frame(rbind(c(1,"10/08/1950","15/03/1998"),
> c(1,"10/08/1950","20/07/1998"), c(1,"10/08/1950","23/10/1998")))
>
> names(df) <- c("ID", "date_birth", "date_exam")
>
> where:
> date_birth: is the date of birth
> date_exam: date of examination
>
> I used the following program to compute the value of the age :
>
> difftime(strptime(as.character(df$date_exam), '%d/%m/%Y'),
> strptime(as.character(df$date_birth), '%d/%m/%Y'))/365.25
>
> which gives me as an output:
>
> > Time differences of 47.59491, 47.94251, 48.20260 days
>
> theses values are actually the 3 ages (but
>
> My questions are:
>
> 1- Why in the output it says "days" instead of "years")
this is in attributes of an output and is not changed by calculations
>
> 2- How can I obtain the output as a numeric vector, without the
> statement "Time difference of ". This is in order to use it in
> my calculations.
as.numeric(as.Date(df$date_exam)-as.Date(df$date_birth))/365
However you can use it in calculations without problem as I suppose
that "Time difference of" results from print method of a difftime
object.
>
> 3- Is there a way quicker and less redondant to compute the age
> form the date_birth and date_exam?
as.Date(df$date_exam)-as.Date(df$date_birth)
HTH
Petr
>
> Thanks a lot,
>
> Bernard,
>
>
>
> -
>
> [[alternative HTML version deleted]]
>
> __
> R-help@stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
> http://www.R-project.org/posting-guide.html
Petr Pikal
[EMAIL PROTECTED]
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[R] Time data
Dear All, I wonder how to compute the age from the date of birth and the date
of examination. Suppose that have the following data:
df <- as.data.frame(rbind(c(1,"10/08/1950","15/03/1998"),
c(1,"10/08/1950","20/07/1998"), c(1,"10/08/1950","23/10/1998")))
names(df) <- c("ID", "date_birth", "date_exam")
where:
date_birth: is the date of birth
date_exam: date of examination
I used the following program to compute the value of the age :
difftime(strptime(as.character(df$date_exam), '%d/%m/%Y'),
strptime(as.character(df$date_birth), '%d/%m/%Y'))/365.25
which gives me as an output:
> Time differences of 47.59491, 47.94251, 48.20260 days
theses values are actually the 3 ages (but
My questions are:
1- Why in the output it says "days" instead of "years")
2- How can I obtain the output as a numeric vector, without the statement
"Time difference of ". This is in order to use it in my calculations.
3- Is there a way quicker and less redondant to compute the age form the
date_birth and date_exam?
Thanks a lot,
Bernard,
-
[[alternative HTML version deleted]]
__
R-help@stat.math.ethz.ch mailing list
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Re: [R] time data
__ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
[R] time data
I have a data set with date, time and rainfall (sample below) my questions are (a) is there a command like as.date for time? and (b) Can R smooth data 6 hourly with such unevenly spaced data? Thanks Carla 09/29/02 19:33 0 09/29/02 19:34 0 09/29/02 19:35 0 09/29/02 19:36 0.1 09/29/02 19:37 0 09/29/02 19:38 0 09/29/02 19:39 0 09/29/02 19:40 0.1 09/29/02 19:41 0 09/29/02 19:42 0 09/30/02 00:00 0 09/30/02 01:50 0.1 09/30/02 02:20 0.1 09/30/02 02:40 0.2 09/30/02 02:50 0.4 09/30/02 05:00 0.7 __ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
