nums <- seq( -1, 1, length.out=7) nums # [1] -1.0000000 -0.6666667 -0.3333333 0.0000000 0.3333333 0.6666667 1.0000000 formatC( nums ) # [1] "-1" "-0.6667" "-0.3333" "0" "0.3333" "0.6667" "1" formatC( nums, digits=2) # [1] " -1" "-0.67" "-0.33" " 0" "0.33" "0.67" " 1" formatC( nums, digits=2, format='f') # [1] "-1.00" "-0.67" "-0.33" "0.00" "0.33" "0.67" "1.00"