index of a mnatrix to negative

hi,

 i have a matrix a =1:10;

 so a(1) = 1 and and a(10)=10

 is it possible to start indexing from say -3.

 so a(-3) = 1, a(-2)=2....a(0)=4,..., and a(6)=10

Answer 1

[Matt Fig]

No. MATLAB has the first index as 1.

Answer 2

[Azzi Abdelmalek]

You can use positive index to represent negative index.

for example if you have to compute y(k)=sin(k) for k=-3:10

 for k=-3:10    
 idx=k+4; % to make index positive
 y(idx)=sin(k)
 end