Hello,
I made the following graphics using Menu → Format → Text Alignment → Align Center.
Would you teach me how to align a graphics center using function?
Plot[Sin, {x, -2*Pi, 2 Pi}, AspectRatio → Automatic]

Use the Style function with the TextAlignment option. Link to the Documentation.
Hello Shenghui,
Your answer is what i want to know.
Thank you.
Yoshihiro Sato