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I want to create a list of 2D matrices
> x
[,1] [,2]
[1,] 1 6
[2,] 2 7
[3,] 3 8
[4,] 4 9
[5,] 5 10
> y
[,1] [,2]
[1,] 301 306
[2,] 302 307
[3,] 303 308
[4,] 304 309
[5,] 305 310
> MATS<-c(x,y)
> MATS[1]
[1] 1
I would like to be able to refer to MATS[1] as if it where x...
228
If we have a list that contain vectors having even number of elements in total then we can create a matrix of those elements. example, if a list contain 8 vectors and the total number of elements in those 8 vectors is 100 or any other multiple of 2 then we can create a matrix of those elements.
If we have a list that contain vectors having even number of elements in total then we can create a matrix of those elements. example, if a list contain 8 vectors and the total number of elements in those 8 vectors is 100 or any other multiple of 2 then we can create a matrix of those elements. This can be done by using unlist function inside ...
Table 1 shows the structure of our first example matrix: It contains five rows and three integer columns. The output of the previous R syntax is shown in Table 2: Another matrix containing character letters. This example demonstrates how to combine multiple matrix objects in a single list.
Matrices are nothing more than a collection of data elements arranged in a rectangular layout that is two-dimensional. An example matrix with 3x3 dimensions looks like this. The most important thing you need to remember to get started with matrices is the matrix () function.
Try
x <- matrix(1:10, ncol=2)
y <- x+300
MATS <- list(x, y) # use 'list' instead of 'c' to create a list of matrices
MATS
[[1]]
[,1] [,2]
[1,] 1 6
[2,] 2 7
[3,] 3 8
[4,] 4 9
[5,] 5 10
[[2]]
[,1] [,2]
[1,] 301 306
[2,] 302 307
[3,] 303 308
[4,] 304 309
[5,] 305 310
Here you have to refer to MATS[[1]] as if it were x
If you want to append a new matrix to the exiting list try
z <- x+500
MATS[[3]] <- z # appeding a new matrix to the existing list
MATS
[[1]]
[,1] [,2]
[1,] 1 6
[2,] 2 7
[3,] 3 8
[4,] 4 9
[5,] 5 10
[[2]]
[,1] [,2]
[1,] 301 306
[2,] 302 307
[3,] 303 308
[4,] 304 309
[5,] 305 310
[[3]]
[,1] [,2]
[1,] 501 506
[2,] 502 507
[3,] 503 508
[4,] 504 509
[5,] 505 510
One drawback of this approach is that you have to know the position in the list where you have to append the new matrix, if you don't know it or simply if you dont want this approach, then here's a trick:
unlist(list(MATS, list(z)), recursive=FALSE) # will give u the same list :D
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