How to plot L-shape domain ?

Hi everyone,

I have a problem with plotting my numerical solution in L-shape domain.

I descritzed the system and using the natural rowwise order of unknowns.

For example, I ordering the system as below:

1 2 3 4 5 6 7 8 9 10

11 12 12 13

14 15 16 17

Then how do I visualize these solution which made by just a single column ?

In my opinion, I need to use "reshape" function. But I don't know how I approach the problem.

I attached one related picture that I want.

Thanks in advances

Best regards,