similar to: What is wrong with this plotting?

I've run into a problem with the datetime axis generated by axis.POSIXct. It appears a similar issue was discussed in October 2003 under the subject line "datetime data and plotting" (see https://stat.ethz.ch/pipermail/r-help/2003-October/039071.html), but I wasn't able to determine whether there is a straightforward solution. The code below produces a graph with apparently

Dear all, I wish to create a POSIXct variable from date and time variables using the ymd_hm function in package lubridate. In some cases data for time is missing, which causes a problem for ymd_hm. I wish to find a smooth way to handle this. # Some example data: x <- data.frame(date = c("2011-09-22", "2011-07-28"), time = c("15:00", NA)) x # paste date and

Dear all, I have a data set containing GPS fixes of animal locations. To check that the GPS's are working properly, I would like to plot the time of the fixes (y-axis) against the date of the fixes (x-axis). If all works well, the plot should show four regular fixes per day. The x-axis should be labelled with month/year (i.e. 11/04) and the y-axis by hour from 00 to 24. I would like to

I am trying to use POSIX datetime objects rather than chron datetime objects but am having difficulty with POSIX in a time series. My question: Once a POSIXct vector is bound to a time series, is there a function to convert back to POSIXct? The following code demonstrates what I am trying to do. > ts(as.POSIXct(strptime(tmp,"%m/%d/%Y %H:%M:%S")),freq=1440) Time Series: Start =

Dear List, I am trying to plot date vs. time, but am having problems getting my y-axis labels how I want them.? When left on its own R plots time at 6 hour intervals from 03:00 to 23:00.? I am wanting 6 hour intervals from 2:00 to 22:00.? I realize yaxp doesn't work in plot(), so I am trying to get it to work in par().? However, now I get the ticks where I want them but the time is output

Hi, I have a casting/formatting question on hist.POSIXt: The histogram plot from POSIXct works perfect (with help of Prof. Ripley -thanks!). When processing the hist(plot=FALSE) output and then plotting the results over the x-axis (bins) coming from hist(), I lose the date/time labels, getting instead integers displayed. Trying to cast the $breaks with as.POSIXct gives silly results with

Date-Time-Stamp input method to correctly interpret user-specific formats:coding is 90% there - based on exmple at http://tolstoy.newcastle.edu.au/R/help/05/02/12003.html ...anyone got the last 10% please? CONTEXT: Data is received where one of the columns is a datetimestamp. At midnight, the value represented as text in this column consists of just the date part, e.g.

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:

I've been using the following code to plot using Sweave in version 1.9.1 library(RODBC) library(lattice) channel <-odbcConnectExcel("h:/water.xls") data <- sqlQuery(channel,"select * from `Sheet1$` where Test = 'TOC' and (Valve='5010-05' or Valve='8030-V26' or Valve='1180-08' or Valve='5040-08')") odbcClose(channel) srt <-

I was wondering why I get <NA> instead of the timestamp in the following. Thanks. > dataDir <- file.path(wd) > localRaw <- read.csv(file.path(dataDir,"LOCAL.csv"), as.is=T,stringsAsFactors = FALSE) > localRaw[1:2,] Year Month Day hour minute second Temp1mab Temp7mab Temp14mab Salinity1mab 1 2009 10 5 0 0 0 11.288 13.675 13.743 33.513

I would like to create a new dataframe from the DateTime column of an existing dataframe and a numeric vector. When I do cbind(x[,1], y) the result is: [1,] 1199370600 12.500 [2,] 1199371200 69.375 [3,] 1199371800 23.750 where the first column you see used to look like: "2008-01-03 08:30:00 Central Standard Time" "2008-01-03 08:40:00 Central Standard Time"

Hi, Using the following simple character vector representing a time series with fractional seconds: datetime <- c("20/09/2011 13:00:59.00", "20/09/2011 13:00:59.02", "20/09/2011 13:00:59.04") Conversion to POSIXct runs into problems; the second element is not interpreted correctly: ---<--------------------cut

I have a data set where the lines look like: 2011-05-13 00:00:00 EONAAL330 dfa13002516PSCNONA 2011-05-13 00:00:01 EONAAL223 laa13044510AS.NONM Some lines are missing the field before and after the NON: 2011-05-13 00:00:05 EONBHS229 mia13001621NON I read them into R using df = read.fwf(file, widths=c(19,-4,7,3,8,2,1,3,1),

OK, I need help!! I've been searching, but I don't understand the logic of some this dataframe addressing syntax. What is this type of code called? test [["v3"]] [is.na(test[["v2"]])] <-10 #choose column v3 where column v2 is == 4 and replace with 10 and where is it documented? The code below works for what I want to do (find the non-missing value in a row),

Hi all, I have run into a problem and some help would be highly appreciated. I have a .csv with the following columns: Date Time Open High Low Close 1/2/2005 17:05 1.3546 1.3553 1.3546 1.35495 1/2/2005 17:10 1.3553 1.3556 1.3549 1.35525 1/2/2005 17:15 1.3556 1.35565 1.35515 1.3553 1/2/2005 17:25 1.355 1.3556 1.355 1.3555 ?. ?.. 2/13/2006 5:20 1.18895 1.18925 1.18835 1.1885 1)

Hi, search on web indicates that R also includes a hist method on POSIXct vectors. My (perhaps too unexperienced) approach below yields an error. Could somebody give me a hint what's wrong ? Peter > str(samples) `data.frame': 7500 obs. of 1 variable: $ DateTime:'POSIXct', format: chr "2006-07-20 00:10:08" "2006-07-20 00:11:17" "2006-07-20

I have two dataframe columns of POXIXct data/times that include seconds. I got them into this format using for example zsort$ETA <- as.POSIXct(as.character(zsort$ETA), format="%m/%d/%Y %H:%M:%S") My problem is that when I subtract the two columns, sometimes the difference is given in seconds, and sometimes it is given in minutes. I don't care which it is, but I need to know which

I have a time series with interval of 2.5 minutes, or 24 observations per hour. I am trying to find a 1 hr moving average, looking backward, so that moving average at n = mean(n-23 : n) The time series has about 1.5 million rows, with occasional gaps due to poor data quality. I only want to take a 1 hour moving average for those periods that are complete, i.e. have 24 observations in the

useRs ? I?m working with the attached data that contains one year?s worth of sub-daily observations of flow (?Q?) and specific conductance (?SC?, a surrogate for concentration) at a point in a stream. The R code posted below shows the extent of data processing thus far. My goal is to create a covariance matrix that takes on the following form: Q1 Q2 ? Q365 SC1 SC2 ? SC365 Q1 Q2 ? Q365

Dear R Community, I am new to R, and have a question that I suspect may be quite simple but is proving a formidable roadblock for me. I have a large data set that includes water-quality measurements collected over many 24-hour periods. The date and time of sample collection are in a combined Date/Time field in the format yyyy-mm-dd hh:mm:ss. I need to be able to subset the data for analysis of