Changing Gears with Correct Ratio - Correct Method?

[potblack2win]

Hi Guys,

Just got my new bike which has 2 gears on front derailer (1 large and 1 small) and has 9 speed cassette on the rear derailer.
I normally use the largest cog at front and switch between gears 5-9 which have been told to prevent cross chaining.

Am I correct in following the chart below

 

[Big John]

I'm confused. You have a double at the front and the diagram is for a triple. So in answer to your original question the answer is no. But the principle is roughly the same.