similar to: apply pairs function to multiple columns in a data frame

Hi All, I have a data set of daily measurements of river flow. I would like to create a "ts" object from this data. Here's a sample data set: date <- as.Date(c(1:300), format="%Y") year=as.numeric(format(date, format = "%Y")) month=as.numeric(format(date, format = "%m")) julianday=as.numeric(format(date, format = "%j"))

Hello, I am having a problem making use of some data outputted from an instrument in a somewhat weird format. The instrument outputs two columns - one called JulianDay.Hour and one called Minutes.Seconds. I would like to convert these columns into a single column with a time. So I was using substr() and paste to extract that info. This works fine for the JulianDay.Hour column as there are always

I've recently stumbled across data.table, Matthew Dowle's package. I'm impressed by the speed of the package in handling operations with large data.frames, but am a bit overwhelmed with the syntax. I'd like to express the SQL statement below using data.table operations rather than sqldf (which was incredibly slow for a small subset of my financial data) or import/export with a

# 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)

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

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

##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),

Hi, I have a data.frame that contains a variable act which records the duration (in seconds) of two states (wet-dry) for several individuals (identified by Ring) over a period of time. Since I want to work with daytime (i.e. from sunrise till sunset) and night time (i.e. from sunset till next sunrise), I have to split act from time[i] till sunset and from sunset until time[i+1], and from time[k]

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

Hi, I'm trying to create a plot showing the density distribution of some shipping data. I like the look of violin plots, but my data is not continuous but rather binned and I want to make sure its binned nature (not smooth) is apparent in the final plot. So for example, I have the number of individuals per vessel, but rather than having the actual number of individuals I have data in the

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.

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

I am working on a simple pilot project comparing the capability of SQL, SAS and R to perform a rolling mean per the following instructions. I have completed the SQL and SAS analysis, so now it's R's turn. Calculate mean values of x (x=count) for each date in the dataset where mean = the average count of days [t-9] through day [t-3] for each date/illness combination. Dataset aggpilot

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

Necesito algo de programación básica para resolver un problema, un inconveniente es que intente "if", cuándo se lo aplico digamos a x <- 5 no hay drama, pero si es a leche$litros me dice que solo se toma el primer elemento. Como pueden ver estoy re perdido. Mi problema: los datos están en un data.frame como el siguiente animal inicio fin control idlactancias

On 1/21/21 8:53 PM, Alfredo Perez wrote: > Is this good news for the "Centos" family? > There is no CentOS "family". CentOS clone is dead and will be now replaced with no-cost RHEL, so in market share (over time) CentOS will be replaced with RHEL. CentOS Stream will be used solely by developers and and entities like Facebook (as a base for their own in house solution).

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'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")))

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]]