convert output matrix to triangular format in R

[TonyMane]

greetings, i enjoy using simka but i have a question regarding manipulating the output files. specifically, is there a way to convert the 'mat_abundance_braycurtis.csv' into a triangular lower matrix. i'm really interested in working with a triangular matrix, much the same as that produced by vegan. for example:

library(vegan)
mat <- matrix(1:9, 3, 3)
mat.dis<-vegdist(mat)
mat.dis
           1          2
2 0.11111111           
3 0.20000000 0.09090909