Rearrange an array based on another array

Question

luca 2019-10-4

评论： luca 2019-10-4

Hi, given the following array

SPI = [1  2   3   4   5  6   7   8   9   10  11  12  13];
VI = [ 5  20  10  15  5  20  10  15  10  15  20  10  5 ];

each value of SPI has a corrispondent value in VI. 1-5 , 2-20 , 3-10 and so on

I have obtained now a new vector SP with all the values that were in SPI

SP = [9 3 11 7 4 2 13 12 8 10 5 6 1]

And I want to obtain a new vector V where I have the corrispondent values of VI for each element of SP.. so:

V = [10 10 20 10 15 20 5 10 15 15 5 20 5]

May someone can help me?

Answer 1

Stephen23 2019-10-4

编辑：Stephen23 2019-10-4

General solution:

>> [~,idx] = ismember(SP,SPI);
>> V = VI(idx)
V =
   10   10   20   10   15   20    5   10   15   15    5   20    5

Solution specifically for your example SPI which is defined as 1:numel(VI):

>> V = VI(SP)
V =
   10   10   20   10   15   20    5   10   15   15    5   20    5

luca 2019-10-4

Thanks