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How to "filter" a matrix using a vector quantity?

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Shane
Shane 2014-7-2
编辑： Star Strider 2014-7-3
I have a matrix [8x3] and a vector quantity that's [6x1].
What I'm trying to do is pick out the three values from the vector within the matrix. Here is the code I'm running.
x=[1;2;3;4;5;6]
x =
1
2
3
4
5
6
y=[1,2,3;2,2,3;3,3,4;4,5,7;5,6,7;6,7,8;7,4,3;8,2,3]
y =
1 2 3
2 2 3
3 3 4
4 5 7
5 6 7
6 7 8
7 4 3
8 2 3
N=y(x)
N =
1
2
3
4
5
6
Obviously my code has more numbers, but essentially the above is what I'm trying to do. However, I want to keep the entire matrix from rows 1 through 6 intact in the answer. Is there any command that can do that? In other words, I want this as the final answer:
N =
1 2 3
2 2 3
3 3 4
4 5 7
5 6 7
6 7 8
I just typed the last part in in, but how do I do that for bigger number sets with a certain command automatically? Thanks

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采纳的回答

dpb
dpb 2014-7-3
Almost there...
N=y(x,:);
the x vector is the row index, : picks up all the columns.
doc colon
for the details. Also might working thru the exercises/examples in the "Getting Started" section on basic array manipulation and addressing...

更多回答（1 个）

Shane
Shane 2014-7-3
That's makes sense.

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