[R] Basic Vector and Matrix Operations

[jim holtman]

For the first case, just extend the vector:

> x<-c(3,4,5)
> x
[1] 3 4 5
> x[5] <- NA
> x
[1]  3  4  5 NA NA
>

the second would use 'which'

On Mon, Jul 7, 2008 at 5:07 PM, Eric Turkheimer <ent3c at virginia.edu> wrote:
> I am wondering if it is possible to perform the following two basic
> functions with primitive R functions.  I know I could write functions for
> either, but it seems as though they are probably built-in somewhere.
>
> 1)  Fill out a vector to a desired length with missing values or zeros.  So,
>
> x<-c(3,4,5)
> f(x,5)
>
> 3,4,5,NA,NA
>
> 2)  Find the [row,col] location of a particular value in a matrix, eg
>
> x<-matrix(1:9,ncol=3)
>
> f(x,2)
>
> 2,1
>
>
> Thanks.
>
> --
> Eric Turkheimer, PhD
> Department of Psychology
> University of Virginia
> PO Box 400400
> Charlottesville, VA  22904-4400
>
> http://www.people.virginia.edu/~ent3c
>
> 434-982-4732
> 434-982-4766 (FAX)
>
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>
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-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

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