How to plot scatter of visual word occurrences in bagOfFeatures command for two categories Positive & Negative.

if true
  imgFolder = fullfile('F:','project','Fyp Data 2','Resize12','mobile');
imgSet1 = imageSet(imgFolder, 'recursive');
bag1=bagOfFeatures(imgSet1);
imgFolder = fullfile('F:','project','Fyp Data 2','Resize12','nomobile');
imgSet2 = imageSet(imgFolder, 'recursive');
bag2=bagOfFeatures(imgSet2);
[feature_v1 words]=encode(bag1,imgSet1);
[feature_v2 words]=encode(bag2,imgSet2);
figure(16)
plot(1:500,feature_v1(1,:),'bo'), hold on,
plot(1:500,feature_v2(1,:),'r*'),
end

Basically i have randomly provided 1:500 here i need something that correctly gives scatter plot?

I am getting this plot after run it but it is not clearly describes the linear svm classification. Basically i want to look my positive & negative Features in same plot to take a look how linearly svm classifier,classify.

please help me to get out of this?