what's in the feature vector returned from extractHogFeatures() ?

I want to analyze the results to determine (myself) if there are directional features that indicate a pattern of lines radiating from a point. I believe I can tell this from the number of counts in the histogram that are orthogonal and within a region. This would allow me to identify a certain type of image compared to others in my dataset.

Or perhaps I should just create my own histogram of oriented gradients? But why reinvent the wheel....

Thanks

Rick