similar to: POSIX problem

Hello R list, This is a question for anyone who has used the by() command. I would like to perform a regression on a data frame by several factors. Using by() I think that I have able to perform this using the following: > lm.r <- by(master, list(Sectionf=Sectionf, startd=startd), function(x) lm (tot.c ~ starttime, data = x)) So that is, I would like to perform separate regressions for

Dear list-members, I would like to calculate the difference between two points in time. To convert a 'time (GMT)'-character with the format "1/1/1999 01:01:01" into an object of class "POSIXct"', I first use the strptime() as suggested in the details help(as.POSIXct). e.g. starttime<-strptime("1/1/1999 01:01:01",format="%d/%m/%Y %H:%M:%S")

I must be stupid because this cannot be this hard. I''m trying to build an all day calendar event. In most clients it shows up as an entry at the top of the day rather than blocking out the whole day with an event. I have a bit of code that looks like this... cal.event do dtstart DateTime.parse("#{startDate.year()}-#{startDate.month()}-#{startDate.day()}") dtend

In file vorbisfile.c, function int ov_pcm_seek_page(OggVorbis_File *vf,ogg_int64_t pos) the calculation of the approximate seek point causes an overflow for very large files and on pure 32 bit architectures. /* take a (pretty decent) guess. */ bisect=begin + (target-begintime)*(end-begin)/(endtime-begintime) - CHUNKSIZE; The temporary expression (target-begintime)*(end-begin)

Hello everybody, I need to calculate seasonal means with temperature data for my work. I have 70 files coming from weather stations, which looks like this for example: startdate <- as.POSIXct("01/01/2006", format = "%d/%m/%Y") enddate <- as.POSIXct("05/01/2006", format = "%d/%m/%Y") date <- seq(from = startdate, to = enddate, by =

Dear R users I am trying to exporting plots from R to an external folder, or to the working directory, but the resolution of plots (pdf file) largely reduced. Any way I can get same quality as my original plots?? e.g. I tested the plotting part using one example and obtained pretty good (/readable) quality for each plot in the (4*4) multiple graph. But when I did the loop and tried to export

Hello, I recently set up a rails application, and wanted to provide helper methods in my model class. I was confused that the class DOESN''T refer to its fields as instance variables. I merely had to type in the field names to be able to work with their data. Here''s an example: I have a "Chessgame" class with a begindate and an enddate. To get the number of hours

Hi, I have a dataframe with many columns, including date and I want to keep only a few of the columns including date column. I used the following command: with(FireDataAppling, cbind(STARTDATE, County, TOTAL, CAUSE) It works, but the date becomes days from Jan 1, 2001. FireDataAppling$STARTDATE[1] gives [1] 2001-01-04 00:00:00 1703 Levels: ......... After the cbind command, the entry

Hi, I have a whole bunch of data, which looks like: 15/03/2003 10:20 1 15/03/2003 10:21 0 15/03/2003 12:02 0 16/03/2003 06:10 0 16/03/2003 06:20 0.5 16/03/2003 06:30 0 16/03/2003 06:40 0 16/03/2003 06:50 0 18/03/2003 20:10 0.5 etc. (times given on a 24 hour clock) and goes on for years. I have some code:

Full_Name: Arni Magnusson Version: 1.6.2 OS: Windows XP Submission from: (NULL) (210.48.49.68) Hi there. I'm experiencing unexpected behaviour from as.POSIXct: > as.POSIXct("1969-12-24") [1] "1969-12-23 23:00:00 New Zealand Standard Time" > as.POSIXlt("1969-12-24") [1] "1969-12-24" > as.POSIXlt("1969-12-24")+1 [1] "1969-12-23

I recently called plot(x,y) where x was an array of POSIXct timestamps, and was pleasantly surprised that it produced a nice plot right out of the box: z <- as.POSIXct(c("2006-10-26 08:00:00 EDT","2007-10-25 12:00:00 EDT")) x <- seq(z[1],z[2],len=100) y <- 1:100 plot(x,y,type="l") The X axis had nice labels, one tick mark every other month. (Plotting on

Hi there, I haven't been on this list until now, so I wasn't aware of this problem until last night ;-) - sorry for that. I am working on a patch for oggCut for that issue (looks good actually but I would like to do some testing befor I can release a patch.) Normal players are not effected by the page time misordering, so I took this issue as "minor". The reason for the

Hi, I render a couple of date_select fields, the HTML looks fine, I can see the values submitted back to the server, but AR doesn''t pick them up from the hash in Booking.new(params[''booking'']). I''ve got a ''booking'' object with parameters product, startdate and enddate. HTML snippets: <select

Regards! During the use of areski a2billing software I'm getting same problem all the time. Actually, after 15 minutes of speaking to someone over calling card, connection brakes. Installation was as smooth as it could be so I don't think I made same kind of a mess in that domain. This is the only problem in the aplication. In the logs everything seems to be fine. I'am sending You

Hi, I would like to make @dates in my controller. I tried the following: startdate = Time.now enddate = startdate.next_week for enddate > startdate @dates << startdate startdate = startdate.tomorrow end But I get an errormessage when I check the syntax: "warning: useless use of a variable in void context" Anyone? Thanks! Steven. -- Posted via

Hi R, How to get the range of values form startDate to lastDate as given below?. #***************************************************************** # Load historical data #****************************************************************** library('quantmod') endDate =Sys.Date() startDate = as.Date(endDate-30, order="ymd") dataspy = getSymbols("SPY", from = startDate,

in my booking / _form I have the following input fields : (startdate and endate) <div> <label for="startdate">Booking Start Date</label><br /> <%= text_field_tag(''startdate'', @startdate, {:class => @startdateclass, :readonly => "readonly", :maxlength => "25"} ) %> <%= observe_field("startdate",

I am using the date_select helper to generate date select elements in a form. I notice that the generated HTML shows that these selects have the following names: Month: current_job[StartDate(2i)] Day: current_job[StartDate(3i)] Year: current_job[StartDate(1i)] I''m assuming that the Xi identifiers somehow specify the appropriate date part from a date or time value. Can anyone

Hi All, I am iterating through dated materials, with variable start and end dates, and would like to skip procedures everytime I encounter a weekend or holiday. To do this, I thought the easiest way would be to create a TRUE/FALSE vector corresponding to each day where it is TRUE if a workday, and FALSE if a weekend or holiday. So far I have been able to do this for weekdays: startDate <-

Hello, fellow R enthusiasts. Ok, I've been racking my brain about this small issue, and between searching the help archives and reading through the plot-related documentation, I can't figure out how to achieve my desired endpoint without some ugly, brute force coding. What I would like to do is make a plot in which only a subset of my data are plotted, but in regular intervals, such as