Understand part of code

Hello, I would appreciate your help, I am new to using Matlab and my programming skills are very basic. Could someone explain to me what this piece of code performs:

axd2i=axd2(:,1);axd2d=axd2(:,2);
axd2i(axd2i==0)=[];axd2d(axd2d==0)=[];
axd2=[axd2i axd2d];
z=0;
y=length (axd2(:,1));
for i=y:-1:1
    if y-i+1==axd2(i,2)
        z=z+1;
    end
end
axd2=axd2(y-z+1:end,:);

It is a program to graph arrows in a structure, but the author is sick with COVID and cannot help me at this time.

Thanks in advance

Answer 1

[KSSV]

axd2i=axd2(:,1);    % get the first column of axd2
axd2d=axd2(:,2);    % get the second column of axd2 
axd2i(axd2i==0)=[]; % remove the elements which are zeros 
axd2d(axd2d==0)=[]; % remove the elements which are zeroes 
axd2=[axd2i axd2d]; % merge them into a column matrix. (May fail if zeroes are different) 
z=0;  % initialize z with 0 
y=length (axd2(:,1)); % get the number of rows/ elements 
for i=y:-1:1
    if y-i+1==axd2(i,2)
        z=z+1;
    end
end
axd2=axd2(y-z+1:end,:);

[Cristian Antonio Vega Cueva]

Thank you very much, you have no idea how much I appreciate the help.