Creating a script with if statements

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Cside 2019-8-30

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评论： Cside 2019-9-2

Hello. I would like to create a script but am still a little new to flow control. I have a matrix A of numbers (100 x 2) , of which I would like to sort them according to whether they fulfill the criteria of having x in column 1 and y in column 2.

So I have this now:

x = 2:4 & y= 2:4

if A(: , 1) == x & A(:,2) ==y;

I would like the script to create a logical matrix as answer for this, should end up with 9 of them.

Thank you!

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Answer 1

Guillaume 2019-8-30

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编辑：Guillaume 2019-8-30

在 MATLAB Online 中打开

In matlab, if statements should be your last resort. By necessity if statements apply to scalars so they tend to force you to use loops.

I'm not very clear on what you're trying to achieve, if you're trying to find all rows of a matrix whose 1st column values re in set x and 2nd column values are in set y, you'd use:

isinset = ismember(A(:, 1), x) & ismember(A(:, 2), y)

If x and y are equal, you could simplify the above to:

isinset = all(ismember(A, [2, 3, 4]), 2)

As you can see, no loop or if required.

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Guillaume 2019-8-30

fixed. Thanks!

Cside 2019-9-2

ah i see, i think rather than creating a script, creating a function will be more ideal for me. Accepted the answer for the new knowledge learnt :) thank you

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