[R] missing values

[Doran, Harold]

You can also explore the classical() function in the MiscPsycho package that does item analysis. 

> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On
> Behalf Of Iasonas Lamprianou
> Sent: Wednesday, December 01, 2010 4:52 AM
> To: Michael Bedward; ivan.calandra at uni-hamburg.de; Rhelp
> Subject: Re: [R] missing values
> 
> thank you, I'll have a go and let you know if i have problems
>  Dr. Iasonas Lamprianou
> 
> 
> 
> 
> Assistant Professor (Educational Research and Evaluation)
> Department of Education Sciences
> European University-Cyprus
> P.O. Box 22006
> 1516 Nicosia
> Cyprus
> Tel.: +357-22-713178
> Fax: +357-22-590539
> 
> 
> 
> 
> Honorary Research Fellow
> Department of Education
> The University of Manchester
> Oxford Road, Manchester M13 9PL, UK
> Tel. 0044  161 275 3485
> iasonas.lamprianou at manchester.ac.uk
> 
> 
> 
> ----- Original Message ----
> From: Michael Bedward <michael.bedward at gmail.com>
> To: ivan.calandra at uni-hamburg.de; lamprianou at yahoo.com; Rhelp
> <r-help at r-project.org>
> Sent: Wed, 1 December, 2010 11:40:13
> Subject: Re: [R] missing values
> 
> And just to add to Ivan's comment, if you are using the rowSums or
> colSums functions with a matrix or data.frame they also have the na.rm
> argument.
> 
> Michael
> 
> On 1 December 2010 20:16, Ivan Calandra <ivan.calandra at uni-hamburg.de> wrote:
> > Hi,
> >
> > (a) sum() and mean() have a na.rm argument that should be set to TRUE.
> >
> > (b) let's try with an example:
> > x <- c(1:5, NA, NA, 6:10, NA)
> > x[is.na(x)] <- 0  ## replace NAs by 0
> >
> > HTH,
> > Ivan
> >
> >
> > Le 12/1/2010 10:00, Iasonas Lamprianou a écrit :
> >>
> >> Dear all,
> >> i have spent a lot of time trying to solve this problem, but I am sure
> >> that
> >> there must be a simple solution. So, as a last resort, I am coming back to
> >> you
> >> again. I have a dataset with some (almost random) values in many
> >> variables. Lets
> >> say that the dataset represents the scores of students to test questions.
> >> What I
> >> need to do is to sum the scores for each student. However, wherever there
> >> is a
> >> missing (NA) value, I cannot get the total score.  How can I compute the
> >> total
> >> score and the average per question (a) by ignoring the missing responses,
> >> (b) by
> >> assuming that a missing response is a zero?
> >> Thank you for the response
> >>
> >>
> >>  Dr. Iasonas Lamprianou
> >>
> >>
> >>
> >>
> >> Assistant Professor (Educational Research and Evaluation)
> >> Department of Education Sciences
> >> European University-Cyprus
> >> P.O. Box 22006
> >> 1516 Nicosia
> >> Cyprus
> >> Tel.: +357-22-713178
> >> Fax: +357-22-590539
> >>
> >>
> >>
> >>
> >> Honorary Research Fellow
> >> Department of Education
> >> The University of Manchester
> >> Oxford Road, Manchester M13 9PL, UK
> >> Tel. 0044  161 275 3485
> >> iasonas.lamprianou at manchester.ac.uk
> >>
> >>
> >>
> >>
> >>
> >> ______________________________________________
> >> R-help at r-project.org mailing list
> >> https://stat.ethz.ch/mailman/listinfo/r-help
> >> PLEASE do read the posting guide
> >> http://www.R-project.org/posting-guide.html
> >> and provide commented, minimal, self-contained, reproducible code.
> >>
> >
> > --
> > Ivan CALANDRA
> > PhD Student
> > University of Hamburg
> > Biozentrum Grindel und Zoologisches Museum
> > Abt. Säugetiere
> > Martin-Luther-King-Platz 3
> > D-20146 Hamburg, GERMANY
> > +49(0)40 42838 6231
> > ivan.calandra at uni-hamburg.de
> >
> > **********
> > http://www.for771.uni-bonn.de
> > http://webapp5.rrz.uni-hamburg.de/mammals/eng/1525_8_1.php
> >
> > ______________________________________________
> > R-help at r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> > and provide commented, minimal, self-contained, reproducible code.
> >
> 
> 
> 
> 
> 
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.