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

[clemaitre]

Hi,
thanks for using simka !
Here is a way in R to transform a square matrix into a triangular one:

mat=as.matrix(read.table("mat_abundance_braycurtis.csv",sep=";", header=TRUE, row.names=1))
mat[upper.tri(mat)]=0

I hope it helps,
Best,
Claire