I have: n-by-3 matrix A, and n-by-1 matrix B:

```
  A=[ x1 y1 z1           
      x2 y2 z2
      x3 y3 z3
      x4 y4 z4
      .......
      xn yn zn ]

B=[ 3           
    2
    7
    1
    ...
    n ]

```

`B` is index (labelling) matrix of `A`. 

I wanna assign the vector `A` to vector `B`.

Ex: 

```
(x1 y1 z1) assign to 1
(x3 y3 z3) assign to 3
......................

```

`(xn yn zn)` assign to `n`

Instead of working with matrix `A`, I can work with "labelling" matrix `B`.
and then

* when I call `3` in matrix `B`, it will show the value (x3 y3 z3) from matrix `A`.
* when I call `7` in matrix `B`, it will show the value (x7 y7 z7) from matrix `A`.
* when I call `[3,7]` in matrix `B`, it will show the value matrix 

```
  `C=[ x3 y3 z3
       x7 y7 z7 ]`

```

from matrix `A`.

* when I call `n` in matrix `B`, it will show the value (xn yn zn) from matrix `A`.
* and vice versa (I call `(x3 y3 z3)` from `A`, it will show `3` in `B`.....)

How to write a code to call matrix `A` from matrix `B` , and vice versa?
(the numbers `3,2,7,1,....n`: in matrix `B` are arbitrary numbers)

Detailed Example:
I have: 6-by-3 matrix A

```
  A=[ 15 2 -1        ---> labelling "1"   
      51 6 -3        ---> labelling "2"
      89 9  1        ---> labelling "3"
      0  4  5        ---> labelling "4"
      0  0  9        ---> labelling "5"
      10 4 -5 ]      ---> labelling "6"

```

.................................
...I will do some algorithm.......
..................................

..................................
And, I get the "labelling matrix B" output result........

```
  B=[ 6           
      1 
      5 ]

```

I wanna to get back the value in matrix A from B-->

```
  C=[ 10 4 -5           
      15 2 -1
      0  0 9 ]

```

How to write a code to show the relationship between A, B,C ? (or how to call matrix C from A &B )