matlab-线性下标

>> a=[1 2 3;4 5 6;7 8 9]

a =

???? 1???? 2???? 3
???? 4???? 5???? 6
???? 7???? 8???? 9

?
>> sub2ind(size(a),1,2)

ans =

???? 4

>> a(4)

ans =

???? 2

>> sub2ind(size(a),2,1)

ans =

???? 2

>> a(2)

ans =

???? 4

>>

?

?