I want to draw an arrow between two nodes (a) and (b), and write text inside the arrow. How can I modify this command to control the size of the arrow head and insert the text?
\draw[->, >=latex, blue!20!white, line width=15pt] (a) to (b) ;
You can perfectly use the shapes library for this. Use
Those are two quite different questions, answering the one in the title:
If you simply add a