could anyone help me to solve the issue

If there are 12 numbers in a row how to select 1,3,5,7,9,11 numbers.

[Stephen23]

@Prabha Kumaresan: surely you can do this! You have asked over two hundred and fifty questions on this forum over the last year. Surely at some point you must have learned something about basic MATLAB indexing! Put in some effort, otherwise you will not learn anything at all.

This is very basic MATLAB, which the introductory tutorials give enough information for you to solve. So for a start, please show us what you have tried so far.

[Stephen23]

@Prabha Kumaresan: please do not close threads that have answers.

Answer 1

[Tiasa Ghosh]

One can check whether the index number is odd or even with

if mod(i,2)==1
  % do something
end

[Stephen23]

True... but why complicate this with mod? Basic indexing is all that is required.

[Stephen23]

@Tiasa Ghosh: from your comment (which you have since deleted):

a=1:12;  % <- yes, good start.
a(1),a(3),a(5)...  % no!

The introductory tutorials, which I linked to in my comment above, give enough information to solve this problem in a much simpler way. Look at the pattern of the indices... why write them separately? Hmmm... does MATLAB possibly have an easy way of generating the sequence 1,3,5,...? Hmmm... maybe I could use this sequence as an index!

[Tiasa Ghosh]

oh yes, I am sorry I deleted that comment. It was:

 a=1:12;  
a(1),a(3),a(5)...

wouldn't this require more manual work?

Answer 2

[Tiasa Ghosh]

Without any loop, this should work:

a=1:12 
a(1:2:end)

Answer 3

[Image Analyst]

If you are going to select 1 number, or 3 numbers, or 5 numbers, or however many numbers you want, you can specify their indexes but you need to decide which one(s). For example, if you are going to select (extract) 3 numbers, which three are they? The first three? The last three? The numbers at indexes 4, 6, and 10? You need some kind of rule.

Or do you want every possible combination of 3 numbers?

For example, let's say you wanted the 3 numbers at indexes 2, 8, and 11, from vector v, you'd do

v3 = v([2,8,11])

[Prabha Kumaresan]

I am having 12 different possible combination. Out of 12 i need to select only 6 which means(1st,3rd,5th,7th,9th and 11th combination)

for example I am having the first combination as

A = 1
A = 2    12
A = 3    10    11
A = 4     7     8     9
A = 5
A = 6

could you please help me on this.