How do I add values to specific values/ specific place of an already existing array?

I have an array of number, t , from which I have extracted some elements at even intervals (every 30 elements, one was extracted) into an array, A.

I now intend to select specific elements in A that meet a condition (if statement), and add x elements to it (x/2 to each side). These new elements to be added are the ones around those specific elements in t (x/2 in each side).

e.g. t = [1.5, 2.5 ,3.5, 4.5, 5.5 ,6.5, 7.5, 8.5, 9.5, 10.5] ;

A = [3.5, 5.5, 7.5],

and in this case I will choose x = 2 elements.

I want to add 2 elements from t to A and finish with A = [ 2.5 ,3.5, 4.5, 5.5 , 6.5, 7.5, 8.5 ]

Answer 1

[Chetan Bhavsar]

@Goncalo Costa will this work for you?

t = [1.5, 2.5 ,3.5, 4.5, 5.5 ,6.5, 7.5, 8.5, 9.5, 10.5]

t = 1×10

1.5000 2.5000 3.5000 4.5000 5.5000 6.5000 7.5000 8.5000 9.5000 10.5000

A = [3.5, 5.5, 7.5]

A = 1×3

3.5000 5.5000 7.5000

x = 2

x = 2

reqx =x/2;

Index = arrayfun(@(x) findstr(x,t),A)

Index = 1×3

3 5 7

finalIndex =[];
for i=1:length(Index)
    finalIndex = [finalIndex Index(i)-reqx:Index(i)+reqx]
end

finalIndex = 1×3

2 3 4

finalIndex = 1×6

2 3 4 4 5 6

finalIndex = 1×9

2 3 4 4 5 6 6 7 8

finalIndexUnique = unique(finalIndex)

finalIndexUnique = 1×7

2 3 4 5 6 7 8

requiredAnswer = t(finalIndexUnique)

requiredAnswer = 1×7

2.5000 3.5000 4.5000 5.5000 6.5000 7.5000 8.5000

[Chetan Bhavsar]

@Walter Roberson Any better way i can handle below line as it changes size on every loop.

finalIndex = [finalIndex Index(i)-reqx:Index(i)+reqx]