How to create a long matrix rapidly

I would like to create the given matrix

0 1 1 1 1 1 1 1 1 1

1 0 1 1 1 1 1 1 1 1

1 1 0 1 1 1 1 1 1 1

1 1 1 0 1 1 1 1 1 1

1 1 1 1 0 1 1 1 1 1

1 1 1 1 1 0 1 1 1 1

1 1 1 1 1 1 0 1 1 1

1 1 1 1 1 1 1 0 1 1

1 1 1 1 1 1 1 1 0 1

1 1 1 1 1 1 1 1 1 0

I thought of using the command "zeros" for the diagonal, and then use "ones", but "ones" does not exist.

For instance:

m=[0 ones(1,9);0 ones(0,9)....]

But that won't work.

How can I make such a matrix with such "condensed" commands instead of writing it out completely?

Thanks

Answer 1

[Mann Baidi]

Hi,

Assuming you would like to create a diagonal matrix with the diagonal as '0' and rest elements as '1'.

You can try the following code:

x=~diag(ones(10,1))

x = 10×10 logical array
   0   1   1   1   1   1   1   1   1   1
   1   0   1   1   1   1   1   1   1   1
   1   1   0   1   1   1   1   1   1   1
   1   1   1   0   1   1   1   1   1   1
   1   1   1   1   0   1   1   1   1   1
   1   1   1   1   1   0   1   1   1   1
   1   1   1   1   1   1   0   1   1   1
   1   1   1   1   1   1   1   0   1   1
   1   1   1   1   1   1   1   1   0   1
   1   1   1   1   1   1   1   1   1   0

For more information on "diag" function, you can refer to the link below:

https://www.mathworks.com/help/matlab/ref/diag.html

Hope this will help in resolving the query!

[Sergio]

Thanks! This is what I looked for indeed.

Answer 2

[Dyuman Joshi]

ones does exist, but using eye would be easier and faster here -

n = 10;
x = 1 - eye(n)

x = 10×10

0 1 1 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1 1 1 1 1 0

[Sergio]

Thanks Dyuman!