[R] The best way for making speciall matrix

[Rui Barradas]

Hello,

Please keep this on the list, R-help is threaded and it becomes part of 
the archives, maybe it will be usefull to others.


You are now asking 2 other different questions.
Are you looking for something like this?

two_values_mat <- function(n, fill = 1, diagonal = 0){
   m <- matrix(fill, nrow = n, ncol = n)
   diag(m) <- diagonal
   m
}
two_values_mat(3)
two_values_mat(3, 0.5, 1)

odd_even_mat <- function(n){
   even <- n %% 2 == 0
   nr <- floor(sqrt(n)) - !even
   nc <- ceiling(n/nr)
   i <- c(0, seq.int(n - even))
   matrix(2*i + !even, nrow = nr, ncol = nc, byrow = TRUE)
}
odd_even_mat(30)
odd_even_mat(17)


Hope this ehlps,

Rui Barradas

Às 11:52 de 23/05/20, Vahid Borji escreveu:
> Thank you Rui,
> Actually, I am making some matrix as follows:
> 0 1 1
> 1 0 1
> 1 1 0
> matrix(rep(c(0,1,1,1),3),nrow=3,ncol=3)
> and
> 1  3   5  7  9  11
> 13  15  17  19
> 21   23  25  27
> 29 31 33 35
> i<-0:17 matrix(2*i+1,nrow=3,byrow=TRUE)
> and
> 1      0.5   0.5
> 0.5     1     0.5
> 0.5   0.5    1
> matrix(rep(c(1,0.5,0.5,0.5),3),nrow=3,ncol=3)
> 
> For all the above matrixes I have written a code (as you see below each 
> matrix) . If you want to make the above matrixes, will you use my codes 
> or will you have other simpler ways for making the above matrixes?
> 
> On Sat, May 23, 2020 at 2:39 PM Rui Barradas <ruipbarradas using sapo.pt 
> <mailto:ruipbarradas using sapo.pt>> wrote:
> 
>     Hello,
> 
>     Use diag() and cbind().
> 
> 
>     special_mat <- function(n){
>         if(n %% 2 != 0) {
>           msg <- paste(sQuote(n), 'is not a multiple of 2, will use')
>           n <- 2*(n%/% 2)
>           msg <- paste(msg, sQuote(n))
>           warning(msg)
>         }
>         x <- diag(n/2)
>         diag(x) <- seq.int <http://seq.int>(n/2)
>         cbind(x, (n/2 + 1):n)
>     }
> 
>     special_mat(6)
>     special_mat(8)
>     special_mat(7)
> 
> 
>     Hope this helps,
> 
>     Rui Barradas
> 
>     Às 10:45 de 23/05/20, Vahid Borji escreveu:
>      > Hi my friends,
>      >
>      > I want to make the below matrix in r:
>      >
>      > 1 0 0 4
>      >
>      > 0 2 0 5
>      >
>      > 0 0 3 6
>      >
>      > I used the below code:
>      >
>      > matrix(c(1,0,0,0,2,0,0,0,3,4,5,6),nrow=3)
>      >
>      > My code works. But I do not like my solution way. I am thinking
>     to find the
>      > simplest way for making this matrix. Do you think my code is the
>     simplest
>      > code for making this matrix? If not, could anyone writes a
>     simpler code
>      > than my one?
>      >
>      >       [[alternative HTML version deleted]]
>      >
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