[R] [External] conditional replacement of elements of matrix with another matrix column

Richard M. Heiberger rmh @end|ng |rom temp|e@edu
Wed Sep 1 23:12:11 CEST 2021

```> A
[,1] [,2]
[1,]   12   NA
[2,]   12   NA
[3,]   12   NA
[4,]   13   NA
[5,]   13   NA
[6,]   13   NA
[7,]   14   NA
[8,]   14   NA
[9,]   14   NA
> B
[,1] [,2]
[1,]   11    6
[2,]   11    7
[3,]   11    8
[4,]   13    9
[5,]   13   10
[6,]   13   11
[7,]   14   12
[8,]   14   13
[9,]   14   14
> C
[,1] [,2]
[1,]   12   NA
[2,]   12   NA
[3,]   12   NA
[4,]   13    9
[5,]   13   10
[6,]   13   11
[7,]   14   12
[8,]   14   13
[9,]   14   14
> same <- A[,1] == B[,1]
> same
[1] FALSE FALSE FALSE  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE

> A[same,2] <- B[same,2]
> A
[,1] [,2]
[1,]   12   NA
[2,]   12   NA
[3,]   12   NA
[4,]   13    9
[5,]   13   10
[6,]   13   11
[7,]   14   12
[8,]   14   13
[9,]   14   14
>

> On Sep 01, 2021, at 16:59, Eliza Botto <eliza_botto using outlook.com> wrote:
>
>> dput(A)
>
> structure(c(12, 12, 12, 13, 13, 13, 14, 14, 14, NA, NA, NA, NA,
> NA, NA, NA, NA, NA), .Dim = c(9L, 2L))
>
>> dput(B)
>
> structure(c(11, 11, 11, 13, 13, 13, 14, 14, 14, 6, 7, 8, 9, 10,
> 11, 12, 13, 14), .Dim = c(9L, 2L))
>
>> dput(C)
>
> structure(c(12, 12, 12, 13, 13, 13, 14, 14, 14, NA, NA, NA, 9,
> 10, 11, 12, 13, 14), .Dim = c(9L, 2L))

```