storing the name AND value of a numeric object in a data frame-CodePudding

I randomly sample values from the first row of matrix A:

                   #1    2    3     4     5    6    7    8    9
A <- matrix(data=c( 0,   0,   0.33, 0.37, 0,   0,   0,   0.3, 0,    #1
                    0,   0,   0,    0,    0.1, 0,   0,   0.9, 0,    #2
                    0.2, 0,   0.1,  0,    0.4, 0,   0,   0.3, 0,    #3
                    0.5, 0,   0,0,  0,    0,   0,   0,   0.5,       #4
                    0,   0.4, 0,0,  0,    0.5, 0,   0,   0.1,       #5
                    0,   0,   0,0,  1,    0,   0,   0,   0,         #6
                    0,   0.2, 0,    0.8,  0,   0,   0,   0,0,       #7
                    1,   0,   0,    0,    0,   0,   0,   0,0,       #8
                    0.1, 0.1, 0.1,  0.1,  0.2, 0.1, 0.1, 0.1, 0.1 ),#9
            nrow=9, ncol=9)

colnames(A) <- c(1:9)
rownames(A) <- c(1:9)


x <- sample(x=A[,1], size=2, prob=A[,1])

The result is a numeric object that looks, for example, like this:

> x
   3    8 
0.33 0.30

The 3 and 8 represent important information that I need to store and use for downstream calculations. I have no idea how to extract them - these row numbers seem to be stored as metadata when I View(x):

How can I reshape the results of sample() so that the numeric object that gets output is a vector containing the row numbers (i.e., in this example, I want x to equal c(3, 8))?

CodePudding user response：

How about:

A <- matrix(data=c( 0,   0,   0.33, 0.37, 0,   0,   0,   0.3, 0,    #1
                    0,   0,   0,    0,    0.1, 0,   0,   0.9, 0,    #2
                    0.2, 0,   0.1,  0,    0.4, 0,   0,   0.3, 0,    #3
                    0.5, 0,   0,0,  0,    0,   0,   0,   0.5,       #4
                    0,   0.4, 0,0,  0,    0.5, 0,   0,   0.1,       #5
                    0,   0,   0,0,  1,    0,   0,   0,   0,         #6
                    0,   0.2, 0,    0.8,  0,   0,   0,   0,0,       #7
                    1,   0,   0,    0,    0,   0,   0,   0,0,       #8
                    0.1, 0.1, 0.1,  0.1,  0.2, 0.1, 0.1, 0.1, 0.1 ),#9
            nrow=9, ncol=9)

colnames(A) <- c(1:9)
rownames(A) <- c(1:9)

x <- names(sample(x=A[,1], size=2, prob=A[,1]))
x
#> [1] "3" "8"

^{Created on 2022-02-01 by the reprex package (v2.0.1)}