R help - Apr 2013 - Need help on matrix calculation

Hello again,

Let say I have 1 matrix:

Mat <- matrix(1:12, 4, 3)
rownames(Mat) <- letters[1:4]

Now I want to subscript of Mat in following way:

Subscript_Vec <- c("a", "e", "b",
"c")

However when I want to use this vector, I am geting following error:

Mat[Subscript_Vec, ]
Error: subscript out of bounds

Basically I want to get my final matrix in following way:

  V1 V2 V3
a  1  5  9
e NA NA NA
b  2  6 10
c  3  7 11

i.e. if some of the element(s) in 'Subscript_Vec' is not in
'Mat' then
that row would be filled by NA, WITHOUT altering the sequence of
'Subscript_Vec'

Is there any direct way to achieve that?

Thanks and regards,

Christofer,

The following should get you started:

r <- Mat[match(rownames(Mat), Subscript_Vec),]
rownames(r) <- Subscript_Vec
r

HTH,
Jorge.-



On Mon, Apr 29, 2013 at 11:38 PM, Christofer Bogaso <
bogaso.christofer@gmail.com> wrote:
> Hello again,
>
> Let say I have 1 matrix:
>
> Mat <- matrix(1:12, 4, 3)
> rownames(Mat) <- letters[1:4]
>
> Now I want to subscript of Mat in following way:
>
> Subscript_Vec <- c("a", "e", "b",
"c")
>
> However when I want to use this vector, I am geting following error:
>
> Mat[Subscript_Vec, ]
> Error: subscript out of bounds
>
> Basically I want to get my final matrix in following way:
>
>   V1 V2 V3
> a  1  5  9
> e NA NA NA
> b  2  6 10
> c  3  7 11
>
> i.e. if some of the element(s) in 'Subscript_Vec' is not in
'Mat' then
> that row would be filled by NA, WITHOUT altering the sequence of
> 'Subscript_Vec'
>
> Is there any direct way to achieve that?
>
> Thanks and regards,
>
> ______________________________________________
> R-help@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.
>
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