Cant solve x*A=y

Hello,

i need to get the solution for:

x*A=y

x=(1xn)unknown
A=(nxm)
y=(1xm)
n>m

I tried x = A'\y';

and x = solve ('x*A=y');

Solve didnt worked at all, and teh upper one seems to work in same cases, but in others it was absolutly wrong:

A =

      -1    -1     1     1     1     0
       0     0     0    -1     0     1
       0     0     0     0     0     0
       1     0     0     0     0     0
       0     1     0     0     0     0
       0     0    -1     0     0     0
       0     0     0     0    -1    -1

y =

       0     0     0     0     0     1

ans =
   -0.0000    0.3333  0   -0.0000   -0.0000  0   -0.3333

Anyone any Idea?

Thanks

Jonas

Answer 1

[David Young]

A is rank-deficient, so there isn't a unique solution.

If you modify A to give it full rank, then

x = y/A

computes x such that x*A is close to y.