Question

I have an array of strings which are actually names of datasets. I perform several measures on each dataset and get result of each measure in a matrix.

I want to save the results of one dataset in some data structure.

So, for example:

We have a string “glass”.
From measurements on dataset “glass” I get 3 matrices a,b,c.
How could I save a,b,c in one structure?

Thanks.

Answer 1

Use a list.

> mydata <- list()
> mydata[[1]] <- matrix(1:4, 2, 2)
> mydata[[2]] <- matrix(1:10, 5, 2)
> mydata[[3]] <- matrix(1:16, 4, 4)
> mydata
[[1]]
     [,1] [,2]
[1,]    1    3
[2,]    2    4

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

[[3]]
     [,1] [,2] [,3] [,4]
[1,]    1    5    9   13
[2,]    2    6   10   14
[3,]    3    7   11   15
[4,]    4    8   12   16

> 
> # To access the first matrix in the list...
> mydata[[1]]
     [,1] [,2]
[1,]    1    3
[2,]    2    4

See ?list for more information.