Sorting and replacing data in matlab

Hi all,

I have a position Array suppose "A"

A =[ 1, 0, 3, 4, 5, 6, 7, 8, 0, 0,15, 20, 10, 9].

I want to replace all those values of A which are grater than 5.

Here, the first element (in A, it is 6) which is grater than 5 will be replaced by a constant say c1

Then next element (in A, it is 7) which is grater than 5 will be replaced by a constant say c2 =c1+ a, where 'a' is a constant

After that the next element (in A, it is 8) which is grater than 5 will be replaced by a constant say c3 =c2+ a, where 'a' is a constant

...... So on.

I want to see the final Array like this

A =[ 1, 0, 3, 4, 5, c1, c2, c3, 0, 0, c4, c5, c6, c7].

N.B. if any element of A is less or equal than 5, the elements of A will be unchanged

Answer 1

[Ameer Hamza]

Here is a vectorized alternative:

A = [ 1, 0, 3, 4, 5, 6, 7, 8, 0, 0,15, 20, 10, 9];
a = 1; c1 = 10;
idx = A > 5;
A(idx) = c1 + (0:nnz(idx)-1)*a;

Result

>> A
A =
     1     0     3     4     5    10    11    12     0     0    13    14    15    16

[Rubel Ahmed]

Thanks Ameer Hamza

Answer 2

[Alan Stevens]

Here's one way:

A =[ 1, 0, 3, 4, 5, 6, 7, 8, 0, 0,15, 20, 10, 9];
c1 = 0.1; a = 0.01;
ix = find(A>5);
for i = 1:numel(ix)
   A(ix(i)) = c1+(i-1)*a; 
end

[Rubel Ahmed]

Thanks Alan Stevens !!