Warning: Matrix is singular, close to singular or badly scaled. Results may be inaccurate. RCOND = NaN. Assignment has more non-singleton rhs dimensions than non-singleton subscripts

I got this error while debugging. what does it mean. how can i fix it? BEM.m is the main code

Answer 1

[Matt J]

The warning message means that you are trying to invert a singular matrix. Use

 >>dbstop if warning

and then re-run to trap the occurrence of this and see if you generated the matrix that you intended.

The error message means that you are trying to do a subscripted assignment, like below, where the right and left sides do not match in size

>> a=rand(3); b=rand(3,3,2);
>> a(1:2,:)=b(1:2,:,:)
Assignment has more non-singleton rhs dimensions than non-singleton subscripts

The usual way to trap these is likewise with the debugger

   >> dbstop if error

[Bishow Shrestha]

where should I use this code? I used in the beginning of the code. What it does is , same like using breakpoints. it stops on the line where error occurs but does not rectify it.

[Matt J]

You call DBSTOP at the command line. Yes, it is like using breakpoints, except that it will break at the moment the error/warning occurs rather than at a point pre-selected by you.

No, it does not rectify the error. It's a tool for you to trace the cause of the bug.

[Bishow Shrestha]

Thanks. Its a useful code.. still I could not understand the singleton dimension error. Is it related to dimension. does LHS and RHS need to be same dimension?

In the error message rhs dimension means Right hand side ? or something else??

[Jan]

@Bishow: Exactly. RHS means "right hand side". The dimensions on both sides of the equal operator do not match.