How to store the output values in matrix?

I have the following program for logistic map function,

function x=logistic(n,level,a,x0)
%Syntax: x=logistic(n,level,a,x0)

if nargin<1 | isempty(n)==1
    n=64;
else
    % n must be scalar
    if sum(size(n))>2
        error('n must be scalar.');
    end
    % n must be positive
    if n<0
        error('n must be positive.');
    end
    % n must be an integer
    if round(n)-n~=0
        error('n must be an integer.');
    end
end

if nargin<2 | isempty(level)==1
    level=0;
else
    % level must be a scalar
    if sum(size(level))>2
        error('level must be scalar.');
    end
    % level must be positive
    if level<0
        error('level must be positive.');
    end
end

if nargin<3 | isempty(a)==1
    a=4;
else
    % a must be scalar
    if sum(size(a))>2
        error('a must be scalar.');
    end
end

if nargin<4 | isempty(x0)==1
    x0=0.1;
else
    % x0 must be scalar
    if sum(size(x0))>2
        error('x0 must be scalar.');
    end
end


% Initialize
x(1,1)=a*x0*(1-x0);

% Simulate
for i=2:n
    x(i,1)=a*x(i-1,1)*(1-x(i-1,1));
    disp(x);
end

% Add normal white noise
x=x+randn(n,1)*level*std(x);

after running the program I get output values as

0.3600

0.9216

0.2890

0.8219

0.5854

0.9708

0.1133

0.4020

0.9616

0.1478

0.5039

0.9999

0.0002

0.0010

0.0039

0.0157

0.0617

0.2317

0.7121

0.8200

0.5904

0.9673

0.1264

0.4416

0.9864

0.0537

0.2034

0.6481

0.9122

0.3203

0.8709

0.4498

0.9899

0.0400

0.1535

0.5199

0.9984

0.0063

0.0251

0.0979

0.3533

0.9139

0.3148

0.8628

0.4736

0.9972

0.0111

0.0440

0.1684

0.5600

0.9856

0.0568

0.2144

0.6738

0.8792

0.4249

0.9775

0.0881

0.3214

0.8724

0.4453

0.9880

0.0473

0.1804

Now I want to store these values in a 8*8 matrix,how to that?

Please do help to where the required line of code should be added to the above program.

Thank you.

Answer 1

[madhan ravi]

Simply reshape x:

reshape(x,8,[]) % or transpose according to your orientation

Note: Preallocating a Variable is an essential step.

[N M Channabasavayya]

how to preallocate a variable?

[Walter Roberson]

x = zeros(n,1);

before you assign to x(1,1)

However, you should not be storing the values in an 8 x 8 matrix. The number of values returned in x is n, which will not necessarily be 64. If you wanted a rectangular matrix, you should factor n to determine the size to make it as a rectangle -- and keep in mind that the user might have provided an n that is a prime number.