How to Speedup conditional vector elements replacement?

Dear,

a is a vector its values correspond to the number of times to repeat the

corresponding number drawn from the vector b. following this rule the result

is a vector c.

as an example:

a=[1 4 1 4 4 1];
b=[1 6 8 3 9 2];
c=[1 6 6 6 6 8 3 3 3 3 9 9 9 9 2] 

Is there any vectorization solution for this proplem?

Regards

Answer 1

[per isakson]

There is a Matlab function, repelem, that does it.

>> repelem( b, a )
ans =
  Columns 1 through 13
     1     6     6     6     6     8     3     3     3     3     9     9     9
  Columns 14 through 15
     9     2
>>   

[Omar Ali Muhammed]

Thanks