How to replace multiple elemets at particular index in vector ?

How to replace multiple elements in particular position inside a vector ?

a = [1 2 3 4 5 6 7 8 9]
% I would like to replace values at index position 3 5 7 to value 0.7 0.1 0.9
% in single operation if possible
a(3) = 0.7;
a(5) = 0.1;
a(7) = 0.9;
a

Answer 1

[madhan ravi]

 a(3 : 2 : 7) = [.7, .1, .9]

[Ole]

Thank you!