Convert Adjacency Matrix Into Edgelist (csv File) For Cytoscape

I have a large (200 columns/rows) adjacency matrix in a csv file. This details interactions between individuals. I would like to convert this file into an edgelist, it can be done

Solution 1:

Get data:

m <- as.matrix(read.table(text="
     A   B   C   D
    A   0   0   0   1
    B   0   0   1   0
    C   1   0   0   1",
   header=TRUE))

How about

w <- which(m==1,arr.ind=TRUE)
data.frame(r=rownames(m)[w[,"row"]],
           i=1,
           c=colnames(m)[w[,"col"]])
##   r i c
## 1 C 1 A
## 2 B 1 C
## 3 A 1 D
## 4 C 1 D

(Do you care about the order ... ?)

PCIT assumes symmetry anyway, so that might be a problem for you.

Solution 2:

with open('input.csv') as infile:
    infile.readline()
    for row in csv.reader(infile, delimiter='\t'):
        src = row[0]
        weights = [int(i) for i in row[1:]]
        for dest, weight in zip("ABC", weights):
            if not weight: continue
            print(src, weight, dest)