Creating a row vector of combinations?

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I have a row vector that 1 by 4. And I know that the minimum and maximum values of the elements in this vector to be -15 and 15. How can I make a matrix that is N by 4 that contains all possible combinations of ALL values?
Let me given an example: min = -15, max = 15, so the result of the code should be a matrix that is N by 4 that will look something like this
A = [[-15,0,0,0];[-14,0,0,0];[-13,0,0,0];[-12,0,0,0];[-11,0,0,0];[-10,0,0,0];[-9,0,0,0];....and so on until the final value vector to be[15,15,15,15]];

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Davide Masiello
Davide Masiello 2023-1-24
You could use nchoosek. The example below is from -3 to 3 for memory issues (you'll generate a humongous matrix). Just substitute -15:15 and the trick is done.
A = nchoosek(-3:3,4)
A = 35×4
-3 -2 -1 0 -3 -2 -1 1 -3 -2 -1 2 -3 -2 -1 3 -3 -2 0 1 -3 -2 0 2 -3 -2 0 3 -3 -2 1 2 -3 -2 1 3 -3 -2 2 3
  9 个评论
Dyuman Joshi
Dyuman Joshi 2023-1-25
Nice work, Davide! I sometimes forget that FEx is an amazing resource as well
And the solution checks out, there should be 7^4 rows total for [-3 3]
7^4
ans = 2401
@Ali Almakhmari, you can obtain the desired solution for the intended range, but it would contain
fprintf('%d rows', 31^4)
923521 rows
so it would be difficult to go through all of them.
Ali Almakhmari
Ali Almakhmari 2023-1-25
Thank you all for your help. You have been amazing!

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更多回答(1 个)

Stephen23
Stephen23 2023-1-25
One simple aprpoach is to download this FEX submission:
but you will need plenty of memory:
V = -3:3
V = 1×7
-3 -2 -1 0 1 2 3
X = combinator(numel(V),4,'p','r');
M = V(X)
M = 2401×4
-3 -3 -3 -3 -3 -3 -3 -2 -3 -3 -3 -1 -3 -3 -3 0 -3 -3 -3 1 -3 -3 -3 2 -3 -3 -3 3 -3 -3 -2 -3 -3 -3 -2 -2 -3 -3 -2 -1
  7 个评论
Stephen23
Stephen23 2023-1-26
编辑:Stephen23 2023-1-26
"What do you mean by copy them?"
Perhaps COPYFILE or one of the WEB* or URL* functions lets you copy from the FEX location to the Answers environment, from whence you could run it. Go and read the documentation and do some experiments. I can't help you with this, I have never tried.
"Also, how did you run the function?"
I downloaded it from FEX, uploaded it here, ran the code, then (out of respect for the submitter's license conditions) deleted the function before submitting my answer. You can delete uploaded files by clicking on the little red "x":
Dyuman Joshi
Dyuman Joshi 2023-1-27
Okay, I'll try it. Thanks for replying.
"I downloaded it from FEX, uploaded it here, ran the code, then (out of respect for the submitter's license conditions) deleted the function before submitting my answer."
Fair enough.

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