Copying and replacing of some values

Hello to everyone,

I would build a function that has to scan all the 'a' vector and in correspondence of the indexes given in 'b' has to create a new vector with almost the same values of 'a' exepted for elements that go from a(2) to a(2+n)changing it with the same value of a(2). The same for a(8) and the values from a(8)to a(8+n) changing these 4 values with the value a(8). Maybe looking at the 'c_final' vector (what I would like to find!!!) could help you better than what I've tried to explain.

a=[1 5 7 11 14 15 16 12 90 33 46 78 79 66];
b=[2 8];

n = 3;

c_final = [1 5 5 5 5 15 16 12 12 12 12 78 79 66];

Thanks in advance and Best regards.

[Juster]

@ Tom = Your solution works fine. @ Babak = Also your solution works fine. @ José-Luis = This function is a bit tricky for me, and give me a final vector longer and different than request(20 > 14) @ Jonathan Sullivan = Unfortunat. also this solution give me a different final vector but it could be a good idea

But let me some time to check it better and I will let you know what will be the best solution.

With best regards,

Jaster

[Juster]

Hello guys,

I would ask you just a little function modification.

Instead of change al the next 'n' value with the first one, I'd like to change it with the previous value.

For example : c_final(3) = c_final(2) ....c_final(4) = c_final(3) etc.

Thanks in advance,

Jaster

Answer 1

[Babak]

 a=[1 5 7 11 14 15 16 12 90 33 46 78 79 66];
 b=[2 8];
 n=3;

 c = a;
 for j=1:length(b)
   if length(a)>b(j)
     index = b(j);
     c(index:index+n)=a(index);
   end
 end
 c = c(1:length(a));
 c

[Juster]

Hello Babak, have you any answer for my addittional question you can find above?

[Babak]

Your question you mean c_final(3) = c_final(2) ....c_final(4) = c_final(3) ?

I don't understand it well. Give an example please.

Answer 2

[Thomas]

Another way

c=a;
for ii=1:length(b)
c(find(c==c(b(ii))):find(c==c(b(ii)))+n)=c(b(ii));
end
c

Answer 3

[Jonathan Sullivan]

It's a little bit of a round about way, but you could leverage MATLAB's strrep function.

c = char(a);
  for ii = 1:length(b)
      c = strrep(c,aorig(b(ii)),char(repmat(aorig(b(ii)),1,n)));
  end
  c = double(c);

Answer 4

[Andrei Bobrov]

c_final = a;
c_final(bsxfun(@plus,b,(0:n)')) = repmat(a(b),n+1,1);