similar to: modify and append new rows to a data.frame using ddply

Hello, I'm having problems working with date values in POSIXct format. Here is what I got (eg.lig attached): x <- read.table("eg.txt", sep = ',', col.names=c("ok","time","secs","lig")) # it gives time as factor z <- cbind(x,colsplit(x$time, split="\\s", names=c("date", "clock")))

My data frame shows changes on the variable act which records the consecutive duration (in seconds) of two states (wet-dry) over a few days for several?individuals (identified by Ring). Since I want to work with daytime (i.e. from dawn till dusk) and night time (i.e. from dusk till next dawn), I have to split act in two: from time[i] till dusk and from dusk until time[i+1], and from time[k] till

# I am sure that I could be more efficient than this but how? Thanks in advance. #GPS in Decimal Degrees in the form longitude latitude RM215 <- matrix(c(-82.1461363, 33.5959109), nrow=1) SC <- matrix(c(-82.025888, 33.606454), nrow=1) RM202 <- matrix(c(-81.9906723, 33.5027653), nrow=1) RM198 <- matrix(c(-81.926823, 33.4634678), nrow=1) HC <- matrix(c(-81.920505, 33.46192), nrow=1)

##This is a function that I am trying to write to calculate sunrise and sunset and works "mostly", but returns nonsensical values. What am I #missing? Thanks in advance. ###remember to include maptools as dependence### library(maptools) sunrise.set <- function(lat, long, date, timezone="UTC", num.days=1){ #this needs to be long lat# lat.long <- matrix(c(long, lat),

I have looked at ?as.POSIXct ?POSIXct and many of the references that are on those pages. I am bewildered with timezones. Is there a way to get what would go into tz="" for making a function that uses POSIXct to be able to be used in all of the timezones in just the united states? This is for both windows and mac... this is the function that I am wanting to use it with

Hello to all, I have two dataframes, the first with two columns sunrise and sunset (for 10 years). Each of these columns is formatted for date time (ex: 01-Jan-2010 15:37:00) In the second data frame I have GPS information and also a date time column (same format ). What I would like to do is a subset of all the rows from the second dataframe that occurred in day time only so between sunrise

Dear R helpers, I have a dataframe (test1) containing the time of sunrise and sunset for each day of the year for 3 years. I have another dataframe (test2) containing measurements that are taken every 15 minutes, 24/7. I would like to extract all rows from test2 that occur between sunrise and sunset for the appropriate date. Can you suggest a good vectorized way to do this? Keep in mind

Are there any functions available to calculate sunrise and sunset times for given latitude,longitude and dates? If not, I'll appreciatte any pointers to C code I could use/port. Thanks, Angel

hi there, does anyone know how to calculate the amount of daylight on every day of the year in R? I mean the time between sunrise and sunset. thanks -- View this message in context: http://r.789695.n4.nabble.com/daylight-tp4647213.html Sent from the R help mailing list archive at Nabble.com.

Does anyone know if there is a sunrise sunset calculator for R? -- Let's not spend our time and resources thinking about things that are so little or so large that all they really do for us is puff us up and make us feel like gods. We are mammals, and have not exhausted the annoying little problems of being mammals. -K. Mullis [[alternative HTML version deleted]]

RM215.sp <- SpatialPoints(RM215, proj4string=CRS("+proj=longlat +datum=WGS84")) d060101 <- as.POSIXct("2006-01-01", tz="EST") study_seq <- seq(from=d060101, length.out=761, by="days") up.215 <- sunriset(RM215.sp, study_seq, direction="sunrise", POSIXct.out=TRUE) down.215 <- sunriset(RM215.sp, study_seq, direction="sunset",

Dear List, I am trying to find each time a value changes in a dataset. The numbers are variables for day vs. night values, so what I am really getting is the daily sunrise and sunset. A simplified example is the following: x<-seq(1:100) y1<-rep(1,10) y2<-rep(2,10) y<-c(y1,y2,y1,y1,y1,y2,y1,y2,y1,y2) xy<-cbind(x,y) I would like to know each time the numbers change. Correct

Hello, ? I have to create a new column from the values of other columns of a data frame. The new?column (y$n) is created imposing a condition (using a third variable y$h) that assigns the values of two time variables (y$b and y$timepos). Here's the piece of code to get there (using the attached files): ? xact <- read.table("act.lig", sep = ',',

Hi ... I wonder if anyone can provide some insight into why the first three examples using the sunriset function (appended below, with results) give the correct answer, but the fourth generates and error. The first two use ISOdatetime with and without a time zone attribute, and the sunriset function returns the correct sunset time. The third and fourth adds 10 seconds to the ISOdatetime

I am very new to R and programming and thank you in advance for your patience and help with a complete novice! I am working with a large multivariate data set that has 10 explanatory environmental variables (e.g. temp, depth) and over 60 response variables (each is a separate species). My data frame is set up like the simplified version below: JulianDay Temperature Salinity Depth Copepod

Hi We have two subnets with routing tables correctly set up so they can both ping to our Sun Solaris Box. 193.71.221 191.9.211 The Sun Solaris box lives on 193.71.221.1 and all PCs on that subnet can map to the Sun box without any problems. All PCs on the 191.9.211 cannot connect to the samba drives giving the error "Network not Found". Any help would be much appreciated. Thanks

I am sure someone must have come across this. Is it possible to force files to binary when copying to Unix directories. NT -> Unix. Text Files have got ^M in them. How do we prevent this happening. Would forcing to binary fix the problem & if so how would this be done? Thanks Ajmal Ajmal Rafique eCommerce +44(0)1384 445564 (Telephone) +44(0)1384 446838 (Fax)

Hi I have created a Mac OS X installer package for installing Asterisk on OSX ver 10.2 and 10.3 Anyone who'd like to give this a try, please download the installer package from here ... http://www.astmasters.net/stuff/Asterisk.pkg.tgz to install Asterisk on OSX just double click the package file. please send any feedback to benjamin (at) sunrise (dash) tel (dot) com NOTE: this is a

Okay, I found the right ahsetup.exe (Active Home). It's doing the same thing for me: extracting CloseApp.exe (which is the same program I found) to the temp folder, but then shutting down with an error message about being unable to use it. As to why, the answer, IMO, is that this is a very old program (the download site says it works in Windows 3.1), and most programs that old simply

Hi all, Eons ago (~2007) Hadley Wickham extremely generously helped me developed a means for plotting temporal activity w/ ggplot. I need to revisit this and have it working again.? I failed to copy the entire legacy code over to my traveling laptop from my workstation, but found a partial bit of the code in an old 2009 Gmail attachment.? I am slated to do a graduate seminar at UF G'ville