Generates 1xN vector (row), symbol values A0 and A1

Hello,

I have a problem. I have an project and i want to:

Generates 1xN vector (row), symbol values A0 and A1, where A0=-A1 and A0=2, p0 is the probabilty to have A0 and is p0=0.5

I have also to replicate first row with N values M times.Each column in the MxN matrix has identical value. I am facing a real problem and i don't know how to do it exactly and correclty.

thank you very much in advance.

[Dyuman Joshi]

Your question is quite unclear. The statement is confusing. What is it that you exactly want to do, and what have you done yet?

For replication, try repmat or repelem, whatever suits your need

[Sotiris Katsimentes]

Good Morning,

Thank you very much.

Let's take it all from the beginning. Practically, I want to create a vector 1xN vector (series), which will take symbol values ​​A0 and A1. A0 and A1 will be opposite to each other, ie A0 = -A1 and A0 will have a certain integer value. However, I want this vector to be created with some possibility. That is, p0 will be the probability that I have the value A0 and I want p0 = 0.5. The first row (vector row) will have a length of N elements that we will define initially and all this will be repeated M times (which will again be defined by the user). All this iteration will be stored in an MxN table that will have unique values ​​Ao and A1.

When I first asked the question I had not managed to do anything until then. However, I have now managed to create this MxN table with the appropriate elements. However the main problem that remains is that these elements in each row do not appear with a probability of p0.

I execute the specific commands:

N = input ('Enter a number \ n');

M = 7

for i = 1: M

x = 2 * round (rand (1, N)) - 1;

mat (i,:) = x;

end

[Dyuman Joshi]

Follow up questions and comments -

• Are A0 and A1, singular values or arrays?
• "However, I want this vector to be created with some possibility. That is, p0 will be the probability that I have the value A0 and I want p0 = 0.5." > I am still not sure what these means.
• You need to define only 1st row, rest you can replicate by using

repelem(y,1,M-1) %y is your initial row (1xN)

[Sotiris Katsimentes]

• Yes A0 and A1 are singular values, for example A0=1 and A1=-1
• In order to make it more understandable for example I want to create such a table. In each line of the vector I want to have an alternation of values A0 and A1, which in this example these values are -1 and 1. I want the probability p0 = 0.5 which means that in each row of the vector to have equal numbers A0 and A1, ie the probability of occurrence ρ0 = 1/2 and respectively ρ1 = 1/2
• thank you very much for your help and idea

Answer 1

[Dyuman Joshi]

A0=1; A1=-A0;
%N=input ('Enter a number \ n');
%check if N is an even number by using ifelse
N=8; %using a random value for example
M=7;
%this is for probablity 0.5
%I think you want all rows to be different so we won't use repmat/repelem
for i=1:M
    z=randperm(N);
    y(i,:)=A0*(rem(z,2)-(~rem(z,2))); %takes in consideration different values of A0
end
y

y = 7×8

-1 1 1 1 -1 -1 -1 1 1 1 1 -1 -1 1 -1 -1 1 -1 -1 -1 1 1 1 -1 1 -1 -1 1 1 -1 -1 1 -1 -1 1 1 -1 1 -1 1 -1 1 -1 1 1 1 -1 -1 1 1 -1 -1 -1 1 1 -1

[Sotiris Katsimentes]

Thank you very much. That was what i wont to manage. Thank you very much for your help.

But can you explain furthermore how you incorporate the possibility p0 in the example above because i didn't understand it very well.

[Dyuman Joshi]

You are welcome!

Since the probability is 50-50 it was easier to do. What I did is generate random permutation of 1 to N. There's a 50-50 chance that a random number from 1 to N will be even or odd. I utilized that. Hope this helps.

[Sotiris Katsimentes]

I have one more question. If i want to generate a vector row with A0 and A1 with this probability p0(for N values),and then replicate it in matrix for M samples, how i can do that ??

as you metioned before "replicate" will be done by "repelem(y,1,M-1) %y is your initial row (1xN)"

So i want to tell me if you know how i can generate the vector row with this feature