Great! Thank you ever so much Rui.
Santi
>________________________________
> From: Rui Barradas <ruipbarra...@sapo.pt>
>To: Santiago Guallar <sgual...@yahoo.com>
>Cc: r-help@r-project.org
>Sent: Wednesday, July 18, 2012 8:29 PM
>Subject: Re: [R] Imposing more than one condition to if
>
>Hello,
>
>You're right. I had thought of this, and I believe there's a day when it
>happens to have a zero in the middle of the day. R doesn't allow
>conditions like the one you've written but it does allow multiple
>conditions, combined using the logical connectives, 'not' - '!', 'or' -
>'|' and 'and' - '&'. Let's see:
>
>Day <- 05:00:00 <= x$clock & x$clock <= 17:00:00
>Night <- !(05:00:00 <= x$clock & x$clock <= 17:00:00) # equal to:
>Night <- x$clock < 05:00:00 | x$clock > 17:00:00
>
>So, you had the first condition reversed and maybe !Day is more readable ;)
>
>(Note: to check if a variable is in an interval, say (a, b), I find it
>better to write a < x & x < b with the interval's end points as
>condition extremes, like Day above. Then if negation is needed half the
>work is already done.)
>
>Anyway, it should be easy to put the compound condition in the function f().
>
>Rui Barradas
>
>Em 18-07-2012 19:02, Santiago Guallar escreveu:
>> Nice! It works. Thank you, Rui
>> There's something that takes me back to the original question, though.
>> The code takes the first value that meets the critical condition (light
>> ==0); however, this value can appear more than once a day because these
>> animals nest in dark caves, and once they are in the logger sensor
>> registers a 0. So, a second condition limiting the time at which the
>> critical condition can be accepted to calculate dusk should be
>> implemented; something like (although R doesn't allow to impose the
>> double condition):
>> if (05:00:00<z$clock> 17:00:00) {zrle <- rle(x$lig == 0)}
>> Santi
>>
>> *From:* Rui Barradas <ruipbarra...@sapo.pt>
>> *To:* Santiago Guallar <sgual...@yahoo.com>
>> *Cc:* r-help@r-project.org
>> *Sent:* Wednesday, July 18, 2012 11:37 AM
>> *Subject:* Re: [R] Imposing more than one condition to if
>>
>> hELLO,
>>
>> There was no nedd to change the names of the variables inside the
>> fucntion. What was going on s that in this new file column 'dtime'
>> doesn't exist. Since column 'clock' exists in all files, I've changed
>> the function once again, making it more general.
>>
>> Note that there is an argument 'colTime' with a default value. In the
>> function's use below I call it with and without that argument.
>>
>>
>> f <- function(x, colTime="clock"){
>> zrle <- rle(x$lig == 0)
>> if(zrle$values[1]){
>> idusk <- sum(zrle$lengths[1:2]) + 1
>> idawn <- zrle$lengths[1] + 1
>> x$dusk <- x[ idusk , colTime ]
>> x$dawn <- x[ idawn , colTime ]
>> }else{
>> idusk <- zrle$lengths[1] + 1
>> x$dusk <- x[ idusk , colTime ]
>> x$dawn <- NA
>> }
>> x
>> }
>>
>> str(d)
>> #d$date <- as.Date(d$date, format="%d/%m%/y")
>>
>> #library(chron)
>> #tm <- times(as.character(d$clock))
>> #d$clock <- tm
>>
>> # See what will happen. This call uses the default 'colTime'
>> bb <- by(d, d$date, f)
>> for(i in seq_along(bb)) print(head(bb[[i]], 1))
>>
>> # call and rbind. This call uses explicit arg 'colTime'
>> do.call(rbind, by(d, d$date, f, colTime="clock"))
>>
>> # Alternatively, it could be, because 'bb' is already created,
>> do.call(rbind, bb)
>>
>>
>> In the code above, I use an optional conversion to date and time
>> classes; as.Date is part of base R, but class times needs package
>> chron.
>> It's a good idea to convert these variables, you can later use, say,
>> arithmetics on dates and times, such as differences.
>>
>> Hope this helps,
>>
>> Rui Barradas
>>
>> Em 17-07-2012 19:53, Santiago Guallar escreveu:
>> > Thank for your time, Rui.
>> > Now, I get this error message:
>> > Error en rbind(deparse.level, ...) :
>> > numbers of columns of arguments do not match
>> > Apparently, some columns have missing values and rbind doesn't
>> work. I
>> > tried:
>> > require(plyr)
>> > do.call(rbind.fill, by(z, z$date, f))
>> > Then the code runs through but dusk the variable dusk is missing and
>> > dawn is filled with NA.
>> > Just in case the problem simply lies in a name, this is your code
>> after
>> > I changed the object names (basically 'x' and 'd' by 'z') to
>> adapt them
>> > to the names of my dataset:
>> > f <- function(z){
>> > zrle <- rle(z$lig == 0)
>> > if(zrle$values[1]){
>> > idusk <- sum(zrle$lengths[1:2]) + 1
>> > idawn <- zrle$lengths[1] + 1
>> > z$dusk <- z$dtime[ idusk ]
>> > z$dawn <- z$dtime[ idawn ]
>> > }else{
>> > idusk <- zrle$lengths[1] + 1
>> > z$dusk <- z$dtime[ idusk ]
>> > z$dawn <- NA
>> > }
>> > z
>> > }
>> >
>> > do.call(rbind, by(z, z$date, f))
>> > Again, I attached a dput() with the object z which contains my
>> dataset.
>> > Santi
>> >
>> > *From:* Rui Barradas <ruipbarra...@sapo.pt
>> <mailto:ruipbarra...@sapo.pt>>
>> > *To:* Santiago Guallar <sgual...@yahoo.com
>> <mailto:sgual...@yahoo.com>>
>> > *Cc:* r-help@r-project.org <mailto:r-help@r-project.org>
>> > *Sent:* Tuesday, July 17, 2012 11:52 AM
>> > *Subject:* Re: [R] Imposing more than one condition to if
>> >
>> >
>> > Hello,
>> >
>> > My code couldn't find the right input columns because your
>> real
>> > data has
>> > different names, it could only find the example dataset's
>> names.
>> >
>> > And there's another problem, my code would give correct
>> answers
>> > with a
>> > limted number of possible inputs and fail with real data.
>> >
>> > Corrected:
>> >
>> >
>> > f <- function(x){
>> > zrle <- rle(x$lig == 0)
>> > if(zrle$values[1]){
>> > idusk <- sum(zrle$lengths[1:2]) + 1
>> > idawn <- zrle$lengths[1] + 1
>> > x$dusk <- x$dtime[ idusk ]
>> > x$dawn <- x$dtime[ idawn ]
>> > }else{
>> > idusk <- zrle$lengths[1] + 1
>> > x$dusk <- x$dtime[ idusk ]
>> > x$dawn <- NA
>> > }
>> > x
>> > }
>> >
>> > do.call(rbind, by(d, d$date, f))
>> >
>> >
>> > One more thing, you are reading your dataset into a data.frame
>> > forgetting that character strings become factors. Try
>> str(d) to
>> > see it.
>> > ('d' is the data.frame.) You could/should coerce the date/time
>> > values to
>> > appropriate classes, something like
>> >
>> >
>> > d$time <- as.character(d$time)
>> > d$time <- as.POSIXct(d$time, format="%d/%m/%y %H:%M:%S")
>> > d$date <- as.character(d$date)
>> > d$date <- as.Date(d$date, format="%d/%m/%y")
>> >
>> >
>> > Hope this helps,
>> >
>> > Rui Barradas
>> >
>> > Em 17-07-2012 07:14, Santiago Guallar escreveu:
>> > > Thank you Rui,
>> > >
>> > > When applied to my original data, your code goes through
>> > although it
>> > > does not produce the correct results: for dusk gives the
>> > first time
>> > > value of next day, for dawn it gives NA. It seems that the
>> > function f
>> > > doesn't find the right input columns.
>> > > A, Ilso had to push up the memory size.
>> > > Attached a file (containing just 3000 of the original c.
>> > 45000 rows)
>> > > after dput().
>> > >
>> > > Santi
>> > >
>> > >
>> > >
>> >
>> ------------------------------------------------------------------------
>> > > *From:* Rui Barradas <ruipbarra...@sapo.pt
>> <mailto:ruipbarra...@sapo.pt>
>> > <mailto:ruipbarra...@sapo.pt <mailto:ruipbarra...@sapo.pt>>>
>> > > *To:* Santiago Guallar <sgual...@yahoo.com
>> <mailto:sgual...@yahoo.com>
>> > <mailto:sgual...@yahoo.com <mailto:sgual...@yahoo.com>>>
>> > > *Cc:* r-help@r-project.org
>> <mailto:r-help@r-project.org> <mailto:r-help@r-project.org
>> <mailto:r-help@r-project.org>>
>> > > *Sent:* Sunday, July 15, 2012 7:21 PM
>> > > *Subject:* Re: [R] Imposing more than one condition
>> to if
>> > >
>> > > Hello,
>> > >
>> > > There are obvious bugs in your code, you are
>> testing for
>> > light > 2 or
>> > > ligth < 2 but this would mean that dusk and dawn are
>> > undetermined for
>> > > light == 2 and that they happen at light == 1.
>> > >
>> > > Without loops or compound logical conditions:
>> > >
>> > >
>> > > f <- function(x){
>> > > x$dawn <- x$time[ which.min(x$light) ]
>> > > x$dusk <- x$time[ max(which(x$light == 0)) + 1 ]
>> > > x
>> > > }
>> > >
>> > > do.call(rbind, by(d, d$day, f))
>> > >
>> > > Hope this helps,
>> > >
>> > > Rui Barradas
>> > >
>> > > Em 15-07-2012 17:32, Santiago Guallar escreveu:
>> > > > Hi,
>> > > >
>> > > > I have a dataset which contains several time
>> records for
>> > a number
>> > > of days, plus a variable (light) that allows to
>> determine
>> > night time
>> > > (lihgt= 0) and daytime (light> 0). I need to obtain get
>> > dusk time
>> > > and dawn time for each day and place them in two
>> columns.
>> > > >
>> > > > This is the starting point (d):
>> > > > day time light
>> > > > 1 1 20
>> > > > 1 12 10
>> > > > 1 11 6
>> > > > 1 9 0
>> > > > 1 6 0
>> > > > 1 12 0
>> > > > ...
>> > > > 30 8 0
>> > > > 30 3 0
>> > > > 30 8 0
>> > > > 30 3 0
>> > > > 30 8 8
>> > > > 30 9 20
>> > > >
>> > > >
>> > > > And this what I want to get:
>> > > > day time light dusk dawn
>> > > > 1 1 20 11 10
>> > > > 1 12 10 11 10
>> > > > 1 11 6 11 10
>> > > > 1 9 0 11 10
>> > > > 1 6 0 11 10
>> > > > 1 12 0 11 10
>> > > > ...
>> > > > 30 8 0 9 5
>> > > > 30 3 0 9 5
>> > > > 30 8 0 9 5
>> > > > 30 3 0 9 5
>> > > > 30 8 8 9 5
>> > > > 30 9 20 9 5
>> > > >
>> > > > This is the code for data frame d:
>> > > > day= rep(1:30, each=10)
>> > > > n= length(dia); x= c(1:24)
>> > > > time= sample(x, 300, replace= T)
>> > > > light= rep(c(20,10,6,0,0,0,0,0,8,20), 30)
>> > > > d=data.frame(day,time,light)
>> > > >
>> > > > I'd need to impose a double condition like the next
>> > but if does
>> > > not take more than one:
>> > > > attach(d)
>> > > > for (i in 1: n){
>> > > > if (light[i-1]>2 & light[i]<2){
>> > > > d$dusk<- time[i-1]
>> > > > }
>> > > > if (light[i-1]<2 & light[i]>2){
>> > > > d$dawn<- time[i]
>> > > > }
>> > > > }
>> > > > detach(d)
>> > > > d
>> > > >
>> > > > Thank you for your help
>> > > > [[alternative HTML version deleted]]
>> > > >
>> > > >
>> > > >
>> > > > ______________________________________________
>> > > > R-help@r-project.org
>> <mailto:R-help@r-project.org> <mailto:R-help@r-project.org
>> <mailto:R-help@r-project.org>>
>> > <mailto:R-help@r-project.org <mailto:R-help@r-project.org>
>> <mailto:R-help@r-project.org <mailto:R-help@r-project.org>>>
>> > mailing list
>> > > > https://stat.ethz.ch/mailman/listinfo/r-help
>> > > > PLEASE do read the posting guide
>> > > http://www.R-project.org/posting-guide.html
>> <http://www.r-project.org/posting-guide.html>
>> > <http://www.r-project.org/posting-guide.html>
>> > > > and provide commented, minimal, self-contained,
>> > reproducible code.
>> > > >
>> > >
>> > >
>> > >
>> >
>> >
>> >
>> >
>> >
>>
>>
>>
>
>
>
>
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