The Documentation for `AspectRatio` on its first line under the "**Details**" section states: "`AspectRatio` determines the scaling for **the final image shape**" (emphasis is mine). But the practice shows that is it not true: it [seems][1] that this option affects only aspect ratio of the plot range but not the aspect ratio of the whole image (with `ImagePadding` and `ImageMargings` added). It is a basic graphics option but we still know a little about it... 

What the option `AspectRatio` actually do? How it interacts with `PlotRangePadding`, `ImagePadding`, `ImageMargings` and `ImageSize`?

It would be ideal to have a ***mathematical model*** of interaction between these options.

  [1]: http://mathematica.stackexchange.com/questions/83766/aspectratio-option-works-unpredictably#comment226656_83771