Help to comment code

Hi, i found an example on the net as to how to get my code to work, but im not entirely sure ow to comment it so that i can understand what each of the functions does, any help??

k=-1:9;
x=[1 2 4 0 0 0];% input x in the form [1,2,3,4,5]
h=[0 1 1 1 1 1];
m=length(x);
n=length(h);
X=[x,zeros(1,n)]; % padding of n zeros
H=[h,zeros(1,m)]; % padding of m zeros
for i=1:n+m-1
  Y(i)=0;
  for j=1:i
      Y(i)=Y(i)+X(j)*H(i-j+1);
  end
end
stem(k,Y,'--rs', 'Linewidth' ,2,...% plot the reponse
  'MarkerEdgeColor','R',...
  'MarkerEdgeColor','B',...
  'MarkerSize',4)
ylabel('Y[n]');
xlabel('n');
title('4.a');
title('4.a: Y1','fontsize', 12)%Title name and characteristics
grid on %puts grid lines into the graph

Answer 1

[Image Analyst]

Put a % symbol, followed by your explanation. Perhaps something like this:

% Initialize variables.
k=-1:9;
x=[1 2 4 0 0 0];% input x in the form [1,2,3,4,5]
h=[0 1 1 1 1 1];
m=length(x);
n=length(h);

% Create new vectors where we append zeros 
% onto the end of the vectors.
X=[x,zeros(1,n)]; % Append n zeros
H=[h,zeros(1,m)]; % Append m zeros

% Create Y vector.
for ki=1:n+m-1
  Y(i)=0;
  for j=1:i
    Y(i)=Y(i)+X(j)*H(i-j+1);
  end
end

% Plot Y as a function of k.
stem(k,Y,'--rs', 'Linewidth' ,2,...% plot the reponse
  'MarkerEdgeColor','R',...
  'MarkerEdgeColor','B',...
  'MarkerSize',4)

% Add titles to plot and axes.
ylabel('Y[n]');
xlabel('n');
title('4.a: Y1','fontsize', 12);
% Add gridlines onto plot area.
grid on;

[Benjamin Garvin]

Thanks for this, I have discovered that when i remove the first for statement i am able to output the same graph, could you tell me why?

[Image Analyst]

That was a typo. It should be i, not ki. I started to change your index to k, because you're not supposed to use i as a loop counter to avoid confusion with the imaginary variable , but then I saw you already had used k so I decided to undo the changes. I guess I didn't hit the undo button enough times. Sorry about that.