Can somebody help me solve how to visualize HOG features without the predefined function (extractHOGFeatures) in matlab?

Hi, I have written the code for extracting HOG Features and I was getting a different answer when I compare with the predefined function in matlab (extractHOGFeatures). Please help me solve the problem and also I want to know the methods to visualize the HOG Features without using the predefined HOG Function (extractHOGFeatures).

Thanks in advance.

I= imread('C:\Aravind\19Spring\ACV\cameraman.png');
I= imresize(I, [128 64]);
Gx= [1, 0, -1];
Gy= Gx';
Ggx= conv2(I, Gx, 'same');
Ggy= conv2(I, Gy, 'same');
Gmag= sqrt(Ggx.^2 + Ggy.^2);
Gdir= atand(Ggy./Ggx);
Gdir= abs(Gdir);
vector= [];
v= [];
vick= [];
[i, j]= size(Gdir);
cell= 8;
block= 16;
count= 0;
for br= 1: cell: i-cell
    for bc= 1: cell: j-cell
        for x= br: cell: br+block-1
            for y= bc: cell: bc+block-1
                bin= zeros(1, 9);
                for m= 0: cell-1
                    for n= 0: cell-1
                        if Gdir(x+m, y+n)>= 0 && Gdir(x+m, y+n)<= 20
                            bin(1)= bin(1)+ ((20- Gdir(x+m, y+n))/20)*Gmag(x+m, y+n);
                            bin(2)= bin(2)+ (Gdir(x+m, y+n)/20)*Gmag(x+m, y+n);
                        elseif Gdir(x+m, y+n)> 20 && Gdir(x+m, y+n)<= 40
                            bin(2)= bin(2)+ ((40- Gdir(x+m, y+n))/20)*Gmag(x+m, y+n);
                            bin(3)= bin(3)+ ((Gdir(x+m, y+n)- 20)/20)*Gmag(x+m, y+n);
                        elseif Gdir(x+m, y+n)> 40 && Gdir(x+m, y+n)<= 60
                            bin(3)= bin(3)+ ((60- Gdir(x+m, y+n))/20)*Gmag(x+m, y+n);
                            bin(4)= bin(4)+ ((Gdir(x+m, y+n)- 40)/20)*Gmag(x+m, y+n);
                        elseif Gdir(x+m, y+n)> 60 && Gdir(x+m, y+n)<= 80
                            bin(4)= bin(4)+ ((80- Gdir(x+m, y+n))/20)*Gmag(x+m, y+n);
                            bin(5)= bin(5)+ ((Gdir(x+m, y+n)- 60)/20)*Gmag(x+m, y+n);
                        elseif Gdir(x+m, y+n)> 80 && Gdir(x+m, y+n)<= 100
                            bin(5)= bin(5)+ ((100- Gdir(x+m, y+n))/20)*Gmag(x+m, y+n);
                            bin(6)= bin(6)+ ((Gdir(x+m, y+n)- 80)/20)*Gmag(x+m, y+n);
                        elseif Gdir(x+m, y+n)> 100 && Gdir(x+m, y+n)<= 120
                            bin(6)= bin(6)+ ((120- Gdir(x+m, y+n))/20)*Gmag(x+m, y+n);
                            bin(7)= bin(7)+ ((Gdir(x+m, y+n)- 100)/20)*Gmag(x+m, y+n);
                        elseif Gdir(x+m, y+n)> 120 && Gdir(x+m, y+n)<= 140
                            bin(7)= bin(7)+ ((140- Gdir(x+m, y+n))/20)*Gmag(x+m, y+n);
                            bin(8)= bin(8)+ ((Gdir(x+m, y+n)- 120)/20)*Gmag(x+m, y+n);
                        elseif Gdir(x+m, y+n)> 140 && Gdir(x+m, y+n)<= 160
                            bin(8)= bin(8)+ ((160- Gdir(x+m, y+n))/20)*Gmag(x+m, y+n);
                            bin(9)= bin(9)+ ((Gdir(x+m, y+n)- 140)/20)*Gmag(x+m, y+n);
                        elseif Gdir(x+m, y+n)> 160 && Gdir(x+m, y+n)<= 180
                            bin(9)= bin(9)+ ((180- Gdir(x+m, y+n))/20)*Gmag(x+m, y+n);
                            bin(0)= bin(0)+ ((Gdir(x+m, y+n)- 160)/20)*Gmag(x+m, y+n);
                        end
                    end
                end
                count= count+ 1;
                v= [v bin];
                if count== 4
                    count= 0;
                    v= v/norm(v, 2);
                    vector= [vector v];
                    v= [];
                end
            end
        end
    end
end