A friend of mine has written a code in unix awk '\BEGIN { OFS = \t; FS = \t} ;\(NR >= 2){\split($3,a,|);\if(a[1]!~ /\?/) {\ print a[1], a[2] > geneinfo_tumor.txt;\ printf %s, a[1] > gene_tumor.txt;\ for (i = 2; i <= 1099; i++) printf \t%g, log($i+1) > gene_tumor.txt;\ printf \n > gene_tumor.txt;}\}' tumor.exp.gt.txtbut I don't understand the following line  for (i = 2; i <= 1099; i++) printf \t%g, log($i+1) > gene_tumor.txt;\what does the log($i+1) do here ??
help understanding a part of an awk program
awk