Replacing 1's in a vector 'a' with elements of another vector 'b' where a and b are not equal?

I have two vectors 'a' and 'b' in the following form:

a=[nan nan 1 1 nan 1 nan 1 1 1 1]

b=[2 3 4 5 6 7 8]

I want to replace all the 1's in vector 'a' by elements in vector 'b' so that I have a vector 'c' in the following shape:

c=[nan nan 2 3 nan 4 nan 5 6 7 8]

I have vectors 'a' and 'b' having thousands of elements and I want to replace all 1's in vector 'a' by elements in vector 'b' .

Please help

Thanks

Answer 1

[Stephen23]

>> a = [NaN,NaN,1,1,NaN,1,NaN,1,1,1,1];
>> b = [2,3,4,5,6,7,8];
>> a(a==1) = b
a =
   NaN   NaN     2     3   NaN     4   NaN     5     6     7     8

[Abdul]

It works fine, thanks!

Answer 2

[Azzi Abdelmalek]

a=[nan  nan  1   1  nan  1  nan  1  1  1  1]
b=[2 3 4 5 6 7 8]
idx=a==1
a(idx)=b(1:sum(idx))

[Abdul]

It works fine, thanks!