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A simple mathematics-based awk solution:

$ cat <<M | awk '{for(i=2;i<=NF;i+=2){printf "%4s",($(i-1)<0?-1:1)*$i}print ""}' -1 2 3 4 -5 9 2 3.2 -4 5 -6 11 M -2 4 -9 3.2 -5 -11 

• Loop from the second (i=2) to the last field (i<=NF).
• Multiply the previous field ($(i-1)) with either -1 or 1.
• Format the output nicely (printf "%4s"), and print a trailing newline (print "").

The only caveat to this is that if you have an odd number of columns, the last field will not display anything at all. I hope this is what you expect. Apparently this is what you expect. :)

(edited to work with decimal values, and to make the loop conditions more aligned with the question while saving 2 characters.)

A simple mathematics-based awk solution:

$ cat <<M | awk '{for(i=2;i<=NF;i+=2){printf "%4s",($(i-1)<0?-1:1)*$i}print ""}' -1 2 3 4 -5 9 2 3.2 -4 5 -6 M -2 4 -9 3.2 -5 

• Loop from the second (i=2) to the last field (i<=NF).
• Multiply the previous field ($(i-1)) with either -1 or 1.
• Format the output nicely (printf "%4s"), and print a trailing newline (print "").

The only caveat to this is that if you have an odd number of columns, the last field will not display anything at all. I hope this is what you expect. Apparently this is what you expect. :)

(edited to work with decimal values, and to make the loop conditions more aligned with the question while saving 2 characters.)

A simple mathematics-based awk solution:

$ cat <<M | awk '{for(i=2;i<=NF;i+=2){printf "%4s",($(i-1)<0?-1:1)*$i}print ""}' -1 2 3 4 -5 9 2 3.2 -4 5 -6 11 M -2 4 -9 3.2 -5 -11 

• Loop from the second (i=2) to the last field (i<=NF).
• Multiply the previous field ($(i-1)) with either -1 or 1.
• Format the output nicely (printf "%4s"), and print a trailing newline (print "").

The only caveat to this is that if you have an odd number of columns, the last field will not display anything at all. I hope this is what you expect. :)

(edited to work with decimal values, and to make the loop conditions more aligned with the question while saving 2 characters.)

A simple mathematics-based awk solution:

$ cat <<M | awk '{for(i=2;i<=NF;i+=2){printf "%4s",($(i-1)<0?-1:1)*$i}print ""}' -1 2 3 4 -5 9 2 3.2 -4 5 -6 11 M -2 4 -9 3.2 -5 -11 

• Loop from the second (i=2) to the last field (i<=NF).
• Multiply the previous field ($(i-1)) with either -1 or 1.
• Format the output nicely (printf "%4s"), and print a trailing newline (print "").

The only caveat to this is that if you have an odd number of columns, the last field will not display anything at all. I hope this is what you expect. Apparently this is what you expect. :)

(edited to work with decimal values, and to make the loop conditions more aligned with the question while saving 2 characters.)

A simple mathematics-based awk solution:

$ cat <<M | awk '{for(i=1;i<=NF-1;i+=2){printf "%4d",($i<0?-1:1)*$(i+1)}print ""}' -1 2 3 4 -5 9  2 3 -4 5 -6 11 M -2 4 -9   3 -5 -11 

• Loop from the first (i=1) to the second-last field (i<=NF-1).
• Multiply the next field ($(i+1)) with either -1 or 1.
• Format the output nicely (printf "%4d"), and print a trailing newline (print "").

The only caveat to this is that if you have an odd number of columns, the last field will not display anything at all. I hope this is what you expect. :)

A simple mathematics-based awk solution:

$ cat <<M | awk '{for(i=2;i<=NF;i+=2){printf "%4s",($(i-1)<0?-1:1)*$i}print ""}' -1 2 3 4 -5 9 2 3.2 -4 5 -6 11 M -2 4 -9 3.2 -5 -11 

• Loop from the second (i=2) to the last field (i<=NF).
• Multiply the previous field ($(i-1)) with either -1 or 1.
• Format the output nicely (printf "%4s"), and print a trailing newline (print "").

The only caveat to this is that if you have an odd number of columns, the last field will not display anything at all. I hope this is what you expect. :)

(edited to work with decimal values, and to make the loop conditions more aligned with the question while saving 2 characters.)