Can someone help me understand this code?

throwAgain=MCO_throwAgain()
function throwAgain=MCO_throwAgain()
die=1;
%Random number 1-6 of a 1x6 vector
RV=randi([1,6],1,6);
flag=0;
while(1)
    for i=1:6
        if(sum(RV==i)>=5)
            flag=1;
            break;
            
        end
    end
    if(flag==1)
        break;
    end
    die=die+1;
    
    RV=randi([1,6],1,6);
end

throwAgain=die;
end

Thank you!

[khalaf Teleb]

Can someone help me understand this code?

function mls_output=mls_generator()

n= input('Enter the order of sequence, n=','s');
random_flag= input ('Enter the random_flag, random_flag= ', 's');

n=str2double(n);
random_flag=str2double(random_flag);

n_big=256; %any MLS larger than this value will be split into seperate files

if n<2
    error('The input order must be 2 or greater')
end

if nargin==1
    random_flag=0;
end

%generate register sequence
%--------------------------
if random_flag==0  %all ones
    register_list=ones(1,n);
elseif random_flag==1 %random
    register_list=round(rand(1,n));
    while sum(register_list)==0 %make sure at least one element is non-zero
        register_list=round(rand(1,n));
    end
else %illegal input for random_flag
    error('random_flag must be either set to zero or one')
end

prim_poly=gfprimdf(n); %obtain the primative polynomial
sum_list=find(prim_poly(1:n)==1); %determine elements from register sequence to be summed

if n<=n_big
    mls_output=zeros(1,2^n-1); %generate empty sequence
    for m=1:2^n-1 %fill the sequence
        %the first element of the register sequence is stored
        mls_output(m)=register_list(1);
        
        %shift the register sequest and determine the new element from the
        %primitate polynomial:
        register_list=[register_list(2:n) mod(sum(register_list(sum_list)),2)];
    end
else
    disp('The specified order is large.  Output will be saved into seperate files and run time will be long.')
    
    split_number=(n+1)-n_big;
    
    for p=1:split_number
        if p==split_number
            mls_output=zeros(1,2^n_big-1); %generate empty sequence
            for m=1:2^n_big-1
                %the first element of the register sequence is stored
                mls_output(m)=register_list(1);
                
                %shift the register sequest and determine the new element from the
                %primitate polynomial:
                register_list=[register_list(2:n) mod(sum(register_list(sum_list)),2)];
            end
            
        else
            mls_output=zeros(1,2^n_big); %generate empty sequence
            for m=1:2^n_big
                %the first element of the register sequence is stored
                mls_output(m)=register_list(1);
                
                %shift the register sequest and determine the new element from the
                %primitate polynomial:
                register_list=[register_list(2:n) mod(sum(register_list(sum_list)),2)];
            end
        end
        eval(['mls_output_',num2str(p),'of',num2str(split_number),'_order',num2str(n),'=mls_output;']);
        disp(['Saving file ',num2str(p),' out of ',num2str(split_number),'.'])
        
        save(['mls_output_',num2str(p),'of',num2str(split_number),'_order',num2str(n)],...
            ['mls_output_',num2str(p),'of',num2str(split_number),'_order',num2str(n)]);
        
    end
    mls_output='saved as files';
end

[John D'Errico]

@khalaf Teleb

I'm sorry, but adding a question as a comment to another unrelated question is a bad idea. Worse, asking for help in understanding a lengthy code like that is asking too much, as we would need to write a compelte user's manual for MATLAb to do that. You just need to learn MATLAB.

Answer 1

[Abolfazl Chaman Motlagh]

function throwAgain=MCO_throwAgain()

define a function named MCO_thorAgain with no input and one output as throwAgain

die=1;

define and set the die vairable to 1 (as a scalar variable)

RV=randi([1,6],1,6);

create an 1x6 Array with integer random numbers between 1 and 6.

flag=0;

define and set the flag vairable to 0 (as a logical vairable)

while 1

will start a while loop and the condition is always true. but in code there is a flag which become 1 and the while loop breaks.

for i=1:6
    if(sum(RV==i)>=5)
        flag=1;
        break;        
    end
end

in each loop the code check for every number between 1 to 6, if number of random numbers in RV which are equal to number i (each number) is greater or equal to 5. in other word the code check if 5 or 6 number of RV is same. so if it is the flag become 1 and the for-loop breaks.

if(flag==1)
    break;
end
die=die+1;
RV=randi([1,6],1,6);
end % end of while

after for-loop ends, the code check if flag is 1. if it is the while loop breaks. if it isn't the scalar die increased by 1 value and RV become new random integer numbers. and while loop continue.

throwAgain=die;
end % end of function

when while loop end. the output of function become the die variable.

which means the output of function is number of times the random integer created but it does not have 5 or 6 same value in it. (first time in loop that RV has 5 or 6 same value the flag become 1 and loop breaks.

throwAgain=MCO_throwAgain()

this line just call the function to execute.

Answer 2

[Chunru]

[throwAgain, RV]=MCO_throwAgain()

throwAgain = 35

RV = 1×6

4 4 4 4 4 1

function [throwAgain, RV]=MCO_throwAgain()
% MCO_throwAgain outputs the number of random throws taken to have at least 5 same
% die points out of 6 dies. Optionally it also outputs the final throw
% points.

die=1;      % 1st throw

%Random number 1-6 of a 1x6 vector
RV=randi([1,6],1,6);        % throw of 6 dies

flag=0;                     % at least 5 same points
while(1)                    % keep trying
    % check if at least 5 dies have same point
    for i=1:6
        if(sum(RV==i)>=5)
            flag=1;
            break;
        end
    end
    
    % if yes, stop
    if(flag==1)
        break;
    end
    
    % Otherwise, throw again
    die=die+1;
    RV=randi([1,6],1,6);
end

throwAgain=die;     % retrurn the number of trials
end