从 R 中的矩阵中提取行和列名称

Question

My file is 1367*1367 long matrix like this-

         MU101188    MU101310   MU101326    MU10251
MU101188    1          0             0          0
MU101310    0          1             0          0
MU101326    0          0             1          0
MU10251     0          0             0          1

I need to extract all pairs for which the value is equal to 1. I m using the following R script which gives me the row and column number, but I also want the names

 Pmatrix = read.csv ("file.csv", header = TRUE, row.names = 1) 
    sig_values <- which(Pmatrix==1, arr.in= TRUE)

Answer 1

Building on the same steps, we can also use logic as below. (Not sure on inbuilt function to return the row,col as one-shot answer). Also tested this code with presence of multiple 1's in rows and it works.

Code snippet below:

Pmatrix = read.csv ("file.csv", header = TRUE, row.names = 1)
sig_values <- which(Pmatrix==1, arr.in= TRUE)

# just check the values
Pmatrix
sig_values

# incase there are multiple 1's in Pmatrix row 
# or one need to sort the order for the row-wise display
sig_values<-sig_values[order(sig_values[,1]),]
# remove the above line, incase there are no multiple 1's in input file or no sorting is desired

# code to get the desired rowname and colname 
i<-1
while (i <= nrow(sig_values)){

      # you can use whatever format and store in variabe or do your processing here
      # e.g. my format was (row,col), hence the paste format
      row_col<-paste("(",dimnames(Pmatrix)[[1]][sig_values[i,1]],",",dimnames(Pmatrix)[[2]][sig_values[i,2]],")")
  print(row_col)
    i<-i+1
}



 #Output
 [1] "( MU101188 , MU101188 )"
 [1] "( MU101310 , MU101310 )"
 [1] "( MU101326 , MU101326 )"
 [1] "( MU10251 , MU10251 )"