similar to: isolating Hour and minute form date and time

Displaying 20 results from an estimated 7000 matches similar to: "isolating Hour and minute form date and time"

2013 Oct 16
1
Extract a predictors form constparty object (CHAID output) in R
I have a large dataset (questionnaire results) of mostly categorical variables. I have tested for dependency between the variables using chi-square test. There are an incomprehensible number of dependencies. I used the chaid() function in the CHAID package to detect interactions and separate out (what I hope to be) the underlying structure of these dependencies for each variable. What typically
2011 Jun 01
3
Identifying sequences
Hallo Everybody Consider the following vector a=1:10 b=20:30 c=40:50 x=c(a,b,c) I need a function that can tell me that there are three set of continuos sequences and that the first is from 1:10, the second from 20:30 and the third from 40:50. In other words: a,b, and c. regards Christiaan [[alternative HTML version deleted]]
2009 May 14
4
Duplicates and duplicated
Hi everybody. I want to identify not only duplicate number but also the original number that has been duplicated. Example: x=c(1,2,3,4,4,5,6,7,8,9) y=duplicated(x) rbind(x,y) gives: [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] x 1 2 3 4 4 5 6 7 8 9 y 0 0 0 0 1 0 0 0 0 0 i.e. the second 4 [,5] is a duplicate. What I want is
2009 Jan 14
2
runs.test in by() statement
Hi everybody I am a recent convert from SAS so please excuse me if this is all very obvious: I want to use the runs test {runs.test() in package tseries} to test the randomness of a certain variable in a survey for each interviewer. I tried to us the by() statement but it doesn't seem to work with runs.test() as the function. Here is what I have: Consider a data frame with two variables and
2011 Jan 21
5
User input in R program
HI Everybody Does anyone know of documentation about different ways of obtaining user input in R. I have used readline() but I wondered is there are sophisticated packages that does things like validate answers or generate selection lists. bets regards Christaan [[alternative HTML version deleted]]
2010 Dec 16
1
Is there a join() function in R ? OR: simulating "Combining ggplot2 and Google Maps" by David Kahle
Hi everybody Im on R version 2.11.1 on Mac OS X I am working through David Kahle's example of using ggplot2 with Rgooglemaps (found here: https://github.com/hadley/ggplot2/wiki/Crime-in-Downtown-Houston,-Texas-:-Combining-ggplot2-and-Google-Maps). Excellent page by the way. I have downloaded the data and the code and want to learn how to do this by first simulating David's results and
2009 Jun 10
1
by and by: using two indices in by() or tapply()
Hi everyone I want to apply a function by two indices. I have a number of surveyors submitting questionnaires. I want to check the time of the first submission for the day for each surveyor and also see a NA is no submission was done on a particular day. This generates a sample of the data:
2011 Aug 12
1
Extract named regions from an Excel file using XLConnect?
Hi Everybody In R, the XLConnect package can read and write named region to and from Excel. In order to read a named region with the readNamedRegion function you need to know it's name. You can check is a name exists with existsName, but you still have to know the name. Is there a way to actually get a list of the named regions in XLConnect sinilar to getRanges in the xlsx package. On that
2011 Mar 14
1
Math characters in column heading using latex() in Hmisc
Hi Everybody I want to print a latex table containing math characters in the column heading These are the formulae I want to use as column headings. It prints OK from TeX $\sum_{i}\sum_{j}C_{P,i,j,y}\times\mathit{FC}_{i}$, $XU_{alt,y}$, $n$, $\bar{C}_{P,y}$ My plan was to create a character vector with these and later rbind the values to them. When I create the vector like:
2009 Oct 07
1
merging dataframes with an unequal number of variables
Hallo Everyone I have the kind of problem that one should never have because one must always plan well and communicate with your team. But now I haven't so here is my problem. I have data coming in on a daily basis from surveys in 10 towns. The questionnaire has 62 variables but some of the regions have used older versions of the questionnaire that have a few variables less. I want to combine
2012 Aug 07
2
Passing arguments to a function within a function ...
Hallo Everybody How do you specify arguments for a function used within another function? Here is my problem: I am reconstructing a calculator for the burden of disease due to air pollution from publications and tools published by the WHO. The calculations make use of published dose-response relationships for particular health end-points. This is then applied to populations with known or
2011 Jul 27
2
Use a list to 'transport' a collection of data sets and results
Hi Everybody I need to "transport" some data and results to use another application (Sweave via LyX - where debugging is very difficult) in order to build a report. Is it possible to store a collection of variables of different types (like named integers, matricies, data frames and two lists) all in one list and save it and then simply load it again later and "unpack" the
2009 Oct 20
1
RPgSQL installation problem
Hi everybody I am trying to install RPsSQL and get the following error message: When I do ./configure form the untarred source directory I get loading cache ./config.cache checking for crypt in -lcrypt... no No crypt function found When I use the Package installer in R I get install.packages("/Users/christiaanpauw/tmp/RPgSQL/", , NULL, type = "source") Warning in
2010 Jan 15
1
Sampling from a Postgres database
Hi Everybody Is there a way in which one can use the RPostgreSQL package to take a sample from a table in Postgres database without having to read the whole table into R regards Christiaan [[alternative HTML version deleted]]
2009 Feb 27
1
Sweave doesn't do csv.get()
Hi Everybody I use R2.8.0 on Mac OS X. I set up LyX 1.6.1 to use Sweave today. I can compile the test file I found on CRAN ( http://cran.r-project.org/contrib/extra/lyx/) without a problem and the output looks very nice. In the test file the following R code is used. <<myFirstChunkInLyX>>= xObs <- 100; xMean <- 10; xVar <- 9 x <- rnorm(n=xObs, mean=xMean, sd=sqrt(xVar))
2009 Feb 12
1
Latex or html output for freq() in prettyR
Hi Everybody I need to create a lot of frequency tables with frequencies and percentages (and cumilative freq and % as well) for a report. freq() in prettyR give more or less what I need. I am trying to export the result of freq() to html but the html doesn't look look the console output. See the following example library(prettyR) library(Hmisc) x <- matrix(sample(1:3, 12,
2009 Jun 17
1
Horisontal line in xtable
Hi everyone (Pardon the incorrect terminology of my previous post: "vertical line...). I have created a function that uses xtable to print table of frequencies and percentages with a heading and some sample information (the sample size and missing values). The function and example data is below. I want a horisontal line that separates the results from the sample information i.e. a
2010 Aug 18
1
Again: wget parameters
Hi Ricardo and everybody In this old post to rhelp you say that the problem was solved but not what the sollution was. I have the same problem now. I want to read a Excel file from a google site that has restricted access so I need to give a username and password at some point. I could not find an example or a help file that shows how this can be done. You post is one of few but it does not
2011 Nov 24
1
Installing rJava from source on Mac
Hi Everybody I am trying to install the latest version of JavaGD from source but get the following error. trying URL 'http://cran.za.r-project.org/src/contrib/JavaGD_0.5-4.tar.gz' Content type 'application/x-gzip' length 102242 bytes (99 Kb) opened URL ================================================== downloaded 99 Kb * installing *source* package ‘JavaGD’ ...
2007 Dec 14
3
How to convert Datetime numbers from Excel to POSIXt objects
Hi all, I need to compare time series data files of different time formats. I had no problems with text format using strptime. But how can I convert datetime numbers from Excel (days since 30.12.1899 00:00:00) into POSIXt objects? For example 29770.375 should be converted to "03.07.1981 09:00:00" I tried the following code and encountered strange results: t1-t0 gives 29770.33