diff --git a/lib/uplot/command/parser.rb b/lib/uplot/command/parser.rb
index 09834de..41d235c 100644
--- a/lib/uplot/command/parser.rb
+++ b/lib/uplot/command/parser.rb
@@ -148,7 +148,7 @@ module Uplot
           MSG
 
           case command
-          
+
           # If you type only `uplot` in the terminal.
           when nil
             warn main_parser.banner
diff --git a/lib/uplot/plot.rb b/lib/uplot/plot.rb
index 3c67c56..fa30ef2 100644
--- a/lib/uplot/plot.rb
+++ b/lib/uplot/plot.rb
@@ -18,7 +18,7 @@ module Uplot
       if series.size == 1
         # If there is only one series, use the line number for label.
         params.title ||= headers[0] if headers
-        labels = Array.new(series[0].size){|i| (i+1).to_s}
+        labels = Array.new(series[0].size) { |i| (i + 1).to_s }
         values = series[0].map(&:to_f)
       else
         params.title ||= headers[1] if headers
diff --git a/lib/uplot/preprocessing.rb b/lib/uplot/preprocessing.rb
index f213e8c..10ee88f 100644
--- a/lib/uplot/preprocessing.rb
+++ b/lib/uplot/preprocessing.rb
@@ -62,12 +62,10 @@ module Uplot
         else
           arr
         end
+      elsif headers
+        transpose2(arr[1..-1])
       else
-        if headers
-          transpose2(arr[1..-1])
-        else
-          transpose2(arr)
-        end
+        transpose2(arr)
       end
     end