Hi. I am a complete novice at matlab and have been asked to create a 10x10 matrix in as few steps as possible. The first row has to be from 1:10, the second line from 2:11 and so on. How can I create this using repmat?

%this is the matrix I want to achieve
A = zeros(10)
A(1,:)=[1:10]
A(2,:)=[2:11]
A(3,:)=[3:12]
A(4,:)=[4:13]
A(5,:)=[5:14]
A(6,:)=[6:15]
A(7,:)=[7:16]
A(8,:)=[8:17]
A(9,:)=[9:18]
A(10,:)=[10:19]
%How can I achieve this using repmat, reshape or meshgrid and the colon
%operator?

[Stephen23]

"How can I achieve this using repmat, reshape or meshgrid and the colon operator?"

Are those really the only operators you are allowed to use?

Answer 1

[Fangjun Jiang]

(1:10)+(0:9)'

[Sam Thorpe]

Thanks Fanjung, but is there any way of doing this using the functions which I specified?

[Fangjun Jiang]

It implies

repmat(1:10,10,1)+repmat((0:9)',1,10)

Answer 2

[Stephen23]

This uses meshgrid and plus as well (not sure if that is allowed):

>> [X,Y] = meshgrid(0:9,1:10);
>> X+Y
ans =
    1    2    3    4    5    6    7    8    9   10
    2    3    4    5    6    7    8    9   10   11
    3    4    5    6    7    8    9   10   11   12
    4    5    6    7    8    9   10   11   12   13
    5    6    7    8    9   10   11   12   13   14
    6    7    8    9   10   11   12   13   14   15
    7    8    9   10   11   12   13   14   15   16
    8    9   10   11   12   13   14   15   16   17
    9   10   11   12   13   14   15   16   17   18
   10   11   12   13   14   15   16   17   18   19

Answer 3

[madhan ravi]

Honestly Fangjun Jiang's answer is the way I would do it but according to your question "How can I create this using repmat?" Which I think is a complete waste of time.

repmat(1:10,numel(1:10),1)+repmat((0:9).',1,numel(0:9))

[Stephen23]

Nice use of repmat to get it onto one line.

Yes, it is a strange and inefficient task. I am still wondering if plus is allowed or not... I guess we will just have to wait for for feedback from Sam Thorpe: what is allowed?

[madhan ravi]

True we should wait:

Another possibilty:

(0:9).' can be replaced with reshape(0:9,1,[])

[Sam Thorpe]

Thank you all very much for your help. It is part of a task for a course which is terrible at teaching us the basics of using the software. The use of plus is allowed. It just asks us to use one of the three functions I specified and the colon operator but gave us no method of using them.

Answer 4

[Jos (10584)]

I think this is the only acceptable answer is, given all restraints:

A = reshape([1:10 2:11 3:12 4:13 5:14 6:15 7:16 8:17 9:18 10:19],10,10)

which does not use numel, tranpose (.'), semi-colons, and plus :-D

But wait a minute, ... is concatenation using square brackets acceptable or not ...