as.matrix(c(1,1)) gives a matrix with only one column, but your function
assumes you have at least two columns (you refer to x[,2]). Please make your
examples reproducible (run it yourself in a fresh instance of R) to obtain best
results with questions on this list.
However, you might just be needing to read about the drop parameter for
indexing:
?"["
which is also mentioned in the Introduction to R document that accompanies the
software in the section on indexing.
---------------------------------------------------------------------------
Jeff Newmiller The ..... ..... Go Live...
DCN:<jdnew...@dcn.davis.ca.us> Basics: ##.#. ##.#. Live Go...
Live: OO#.. Dead: OO#.. Playing
Research Engineer (Solar/Batteries O.O#. #.O#. with
/Software/Embedded Controllers) .OO#. .OO#. rocks...1k
---------------------------------------------------------------------------
Sent from my phone. Please excuse my brevity.
On December 16, 2014 10:55:27 PM PST, Sachinthaka Abeywardana
<sachin.abeyward...@gmail.com> wrote:
>I have the following cost function:
>cost<-function(x){
> x[,1]*sin(4*x[,1])+1.1*x[,2]*sin(2*x[,2])
>}
>
>If I send in a matrix which has MORE than one row and 2 columns, this
>works fine. However, if I try to do cost(t(as.matrix(c(1,1)))) it
>gives me an index error. When I tried debugging it, I found that the
>type of matrix 'x' was converted to numeric.
>
>How do I prevent this conversion from matrix to numeric if its a
>matrix with just one row? The only way it would work is if I have:
>x[1]*sin(4*x[1])+1.1*x[2]*sin(2*x[2]), which in turn wont work with a
>matrix input.
>
>Thanks,
>Sachin
>
>______________________________________________
>R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
>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@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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.
