How to denote letters to mark significant differences in a bar chart plot
I want to mark significant differences between two bars with different letters (like bar1:a and bar2:b). If there is no significant differences between two bars they get the same letter (like bar1:a and bar3:a). Sort the right letters to the bars gets much more complex when the number of bars increases. I have several hundreds of statistical comparisons here and have to find a computer program that can generate the letters from the data for me.
Anybody an idea which programme can help me?
I have added an example plot with letter-coded significant differences to illustrate what I want to do.
*** If any one can help me to obtain a good reference material that guide to Interpretation and analysis of biological research data would be much grateful.
Attached a sample e.g.