Explicitly providing nrow and ncol to `as.matrix` does not create dimensions

Question

I am creating a simple 3x3 matrix with 9 values using the as.matrix() function. But the output I am seeing seems to be incorrect. What am I missing?

Here's what I am doing:

> s <- as.matrix(c(3,4,5,6,7,8,9,10,11),nrow = 3,ncol = 3)

What I expect to see:

> s
     [,1] [,2] [,3]
[1,]    3    6    9
[2,]    4    7   10
[3,]    5    8   11

But What I actually see:

> s
      [,1]
 [1,]    3
 [2,]    4
 [3,]    5
 [4,]    6
 [5,]    7
 [6,]    8
 [7,]    9
 [8,]   10
 [9,]   11
>

What am I missing?

The documentation for as.matrix() function says that nrow and ncol are used to defined the desired number of rows and columns. Any pointers?

To reiterate what @RonakShah said, if you look as the documentation for as.matrix vs. simply matrix, you will see that their API is different. matrix takes the arguments you have in your example (i.e. nrow and ncol) however as.matrix has the ellipsis ... as its second argument which are "additional arguments to be passed to or from methods". — Joseph Wood

Ronak Shah Ronak Shah · Accepted Answer · 2018-09-28T01:32:43

as.matrix has no nrow and ncol parameter. What you need is actually matrix. Check ?as.matrix

matrix(c(3,4,5,6,7,8,9,10,11),nrow = 3,ncol = 3) 

#     [,1] [,2] [,3]
#[1,]    3    6    9
#[2,]    4    7   10
#[3,]    5    8   11