hello i need to write script mathlab to make a matrix with vector v=[1 2 3 4]

the output is [1 1 1 1;2 4 8 16;3 9 27 81;4 16 64 256]

[Walter Roberson]

http://www.mathworks.com/matlabcentral/answers/6200-tutorial-how-to-ask-a-question-on-answers-and-get-a-fast-answer

Hint: Use .^

[Mohamad Haj]

Thank you for help a=[1,2,3,4]; for i=2:4 a(i,:)=a((i-1),:).^2

end i do this code but there is an error in it and I don't know where

Answer 1

[Awais Saeed]

Seems you want to have powers from 1 to 4

v = 1:4;
bsxfun(@power,v(:),[1:4]) % poers ranging from 1 to 4

ans = 4×4

1 1 1 1 2 4 8 16 3 9 27 81 4 16 64 256

[Walter Roberson]

Note that this was a homework question. It would have been better to guide the poster instead of giving them the entire answer.

[Awais Saeed]

Yes I realized that after seeing your comment. I had my answer window opened up while doing other stuff on other browser tabs. Its strange that people do not even try to google the problem.

[Mohamad Haj]

Thank you for you answer

a=[1,2,3,4];
for i=2:4
 a(i,:)=a((i-1),:).^2
end

i do this code but need editing can you help me

[Walter Roberson]

Think about row 2, when i = 2. a(i-1,:) would be [1,2,3,4] . You would square that to get [1, 4, 9, 16] -- okay, that's the result you want in the second column.

Now think about row 3, when i = 3. a(i-1,:) would be [1,4,9,16]. You would square that to get [1,16,81,256]. Okay, that's the result you want in the 4th column.

But... how can you get the result you want for the third column? 27 is not the square of any integer, so you cannot get it using the technique you are using.

[Awais Saeed]

• Take transpose of vector a to make it a row vector.
• Take square of a and put the result in second column
• Take cube of a and put the result in third column.
• Use index of for loop with .^ to take square, cube, etc

[Mohamad Haj]

I will try it