Using "for" to create loops

2016 7 6
1 个回答
回答已采纳
更新时间：2016 7 6
3 次查看（30 天）

0 个投票

I am trying to create a loop to have a (ixm)x2 matrix such as:
1 1
1 2
1 3
2 1
2 2
2 3
3 1
3 2
3 3
My formulation is as follows:
i = size(input,1);
m = max(input(:,5));
for indice = 1:i;
for indice2 = 1:m;
Zassign = (1,[indice, indice2]);
end
end
I am missing something in here. If you may help me, I would really appreciate it.

1 个评论
显示 -1更早的评论 隐藏 -1更早的评论

Taner Cokyasar
Taner Cokyasar 2016-7-6
编辑：Stephen23 2016-7-6
If possible, can I also write a matrix as following:
Z 1 1
Z 1 2
Z 1 3
Z 2 1
Z 2 2
Z 2 3
Z 3 1
Z 3 2
Z 3 3
I am a new MATLAB user. I know MATLAB deals with numbers. However, I just wanted to ask to make sure if that is not possible.

请先登录，再进行评论。

请先登录，再回答此问题。

 采纳的回答

Stephen23
Stephen23 2016-7-6
编辑：Stephen23 2016-7-6

1 个投票

Why waste time with a loop? Code vectorization is much more beautiful!
>> [X,Y] = meshgrid(1:3);
>> mat = [X(:),Y(:)]
mat =
1 1
1 2
1 3
2 1
2 2
2 3
3 1
3 2
3 3
And if you really want the Z's you can print them, but they cannot be stored in a numeric matrix (unless you store the character code):
>> fprintf(' Z %d %d\n',mat.')
Z 1 1
Z 1 2
Z 1 3
Z 2 1
Z 2 2
Z 2 3
Z 3 1
Z 3 2
Z 3 3

7 个评论
显示 5更早的评论 隐藏 5更早的评论

Taner Cokyasar
Taner Cokyasar 2016-7-6
编辑：Taner Cokyasar 2016-7-6
It definitely works Stephen. Thank you so much for those. I have one more question. What if I want to add a column vector at the end of mat. The column vector I am talking is the result of my question. I just want to show results matched with its corresponding variables.
Let's say:
Z 1 1 0
The zero at the end represents the answer for the variable Z11. I have a column vector of answers for each variable named as "Zvalues".
Stephen23
Stephen23 2016-7-6
编辑：Stephen23 2016-7-6
You can use much the same idea. If the results are in a vector Z, then simply concatenate it onto the back:
>> Z = 1:9;
>> [X,Y] = meshgrid(1:3);
>> mat = [X(:),Y(:),Z(:)]
mat =
1 1 1
1 2 2
1 3 3
2 1 4
2 2 5
2 3 6
3 1 7
3 2 8
3 3 9
and for printing you just need to add the appropriate formatting operator to the fprintf string:
>> fprintf(' Z %d %d %d\n',mat.')
Taner Cokyasar
Taner Cokyasar 2016-7-6
You are great Stephen! "%d" was what I was missing. God Bless!
Stephen23
Stephen23 2016-7-6
@Taner Cokyasar: you should read the fprintf documentation carefully, because there are a lot of options for these formatting operators. Practice and try them to pick one that best suits your needs.
Taner Cokyasar
Taner Cokyasar 2016-7-6
编辑：Taner Cokyasar 2016-7-6
Actually meshgrid is not working for this situation. I just chose a lucky example by using i=3 and m=3. When I tried i=10 and m=3, it doesn't work. Do you have any idea? I mean:
1 1
1 2
1 3
2 1
2 2
2 3
3 1
3 2
3 3
4 1
4 2
4 3
.
.
.
10 1
10 2
10 3
Stephen23
Stephen23 2016-7-6
编辑：Stephen23 2016-7-6
Did you read the meshgrid documentation ? You can use two inputs to meshgrid:
>> [X,Y] = meshgrid(1:10,1:3);
>> mat = [X(:),Y(:)]
mat =
1 1
1 2
1 3
2 1
2 2
2 3
3 1
3 2
3 3
4 1
4 2
4 3
5 1
5 2
5 3
6 1
6 2
6 3
7 1
7 2
7 3
8 1
8 2
8 3
9 1
9 2
9 3
10 1
10 2
10 3
Taner Cokyasar
Taner Cokyasar 2016-7-6
After this answer, yes :) I appreciate it.

请先登录，再进行评论。

更多回答（0 个）

类别

在 帮助中心 和 File Exchange 中查找有关 Loops and Conditional Statements 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by