How can i extract parameters from a vector at specific values

Hi everyone,

i looking for a way to get in a new vectore 'D' , values of a vectore 'A' when the values of B are equal to the values of C

lets say i have A = [1,2,3,4,5,7,8,9,10]

and B =[11,12,13,14,15,16,17,18,19,20] ; both A and B of the same lenght,

i want to compare B with a new vector C = [11,15,20]

that returns values in A when B=C

expected output D=[1,5,10]

[Stephen23]

"both A and B of the same lenght, "

Your examples have different lengths:

>> numel(A)
ans =  9
>> numel(B)
ans =  10

[Gisela Alejandra Peña Sanchez]

i missed the number 6 in A, it was only an example

Answer 1

[Stephen23]

Use ismember:

>> A = 1:10
A =
    1    2    3    4    5    6    7    8    9   10
>> B = 11:20
B =
   11   12   13   14   15   16   17   18   19   20
>> [idx,idy] = ismember(C,B);
>> D = A(idy(idx))
D =
    1    5   10

[Gisela Alejandra Peña Sanchez]

perfect, thank you so much!