Hi Fabricia,
nobody will be able to answer you if you don't provide the data and/or code
you are using. See for example
http://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example/5963610#5963610
If you send me the tree, I can try to figure out what is going wrong.
Klaus
Hi!
I am using the function midpoint of package phangorn to root my trees
(which I generated by simulations).
A negative branch length is added to my tree after I use the midpoint
function. The same does not happen if I use FigTree for example.
Does anyone know why that happens?
I cannot have
