could anyone help me how to generate some of the similar values using rng

If i execute the code some both x and y remains same

s = rng
x = rand(1,5)
rng(s)
y=rand(1,5)

But i want three values to be same and the remaining two values to be different.

Could anyone please help me on this.

Answer 1

[the cyclist]

Here is a new answer, based on the comments on the other answers.

numberTotal  = 8; % You can change this to 1000
numberRepeat = 3; % You can change this to 200

% rng default

% Generate two full vectors of independent randoms
x = rand(1,numberTotal);
y = rand(1,numberTotal);

% Generate random, non-repeated indices to copy some locations from x to y
indexRepeat = randperm(numberTotal,numberRepeat);

% Overwrite the leading y values from x.
y(indexRepeat) = x(indexRepeat);

x

x = 1×8

0.5267 0.0600 0.3075 0.2606 0.7846 0.8719 0.3408 0.3655

y

y = 1×8

0.4232 0.0600 0.3023 0.5271 0.7846 0.2124 0.3408 0.3699

This code will replace a fixed number of elements, but the positions that are replaced will be random. If you need to replace a random number of elements, then use something like

numberRepeat = randi([3,5]);

which will repeat 3, 4, or 5 elements.

Answer 2

[the cyclist]

Is this what you mean?

rng default % for reproducibility, if desired
[repmat(rand(),1,3) rand(1,2)]

ans = 1×5

0.8147 0.8147 0.8147 0.9058 0.1270

[jaah navi]

I want to x and y in the following manner.

x= [0.1419    0.4218    0.9157    0.7922    0.9595]
y= 0.1419    0.4218    0.9157    0.6134    0.8234]

As my x and y size is larger (1,1000) i need around 800 values in x should remain same as in y and the rest 200 values can be different.

Could you please help me on this.

Answer 3

[the cyclist]

In response to the comment in my other answer, here is a pretty simple way to do it:

numberRep = 3; % You can change this to 800
numberNew = 2; % You can change this to 200

rng default

% Generate two full vectors of independent randoms
x = rand(1,numberRep + numberNew);
y = rand(1,numberRep + numberNew);

% Overwrite the leading y values from x.
y(1:numberRep) = x(1:numberRep);

x = 1×5

0.8147 0.9058 0.1270 0.9134 0.6324

y = 1×5

0.8147 0.9058 0.1270 0.9575 0.9649

Until the number you need gets really large, generating a few spurious numbers in y and overwriting them doesn't matter.

[jaah navi]

ok. Instead of being continuous similar values can it be discontinuous in the following manner.

x= [0.1419    0.4218    0.9157    0.7922    0.9595]
y= [0.1419    0.6134    0.9157    0.6134    0.9595]

[the cyclist]

I am not going to guess again at what you want, only to have you give another small detail. Please give a complete explanation of what you need, with all the details.

For example ...

• do you always want the same number of elements copied?
• are the copied elements always in a known position?
• do you want the positions of the copied elements to also be random?
• etc.

[jaah navi]

ok. for example

A=[ 2 3 4 5 6 7 8 9]

and

B=[11 12 13 14 15 16 17 18 ]

I want to have B such that

B=[11 12 4 14 15 7 8 18]

Here you can see as 4 is present in third place it is also present in third place of B. Similarly 16 and 17 in B is replaced by 7 and 8 as present in A.

This is for small size. But I need to have solution for larger size.

Could you please help me on this.

[the cyclist]

You did not answer any of the questions I asked in my previous comments.

How do you know which elements to copy? Do you have a fixed list of positions, such as ...

copyList = [3 6 7];

Or do you choose which elements to copy at random?

How many elements should be copied? 100? 200? Half the length of the vector?

[jaah navi]

I need to copy a random number of elements.

The copied elements position should remain the same in both matrices.

Majority of the randomly copied elements should be same (90/100).