diff --git a/lib/uplot/command.rb b/lib/uplot/command.rb
index ade404e..80f8016 100644
--- a/lib/uplot/command.rb
+++ b/lib/uplot/command.rb
@@ -29,6 +29,10 @@ module Uplot
       case @ptype
       when 'hist', 'histogram'
         histogram(input_lines).render
+      when 'line', 'lineplot'
+        line(input_lines).render
+      when 'lines'
+        lines(input_lines).render
       end
 
       puts input_lines if @params[:p]
@@ -38,5 +42,32 @@ module Uplot
       series = input_lines.map(&:to_f)
       UnicodePlot.histogram(series, nbins: @params[:nbins])
     end
+
+    def line(input_lines)
+      x = []
+      y = []
+      input_lines.each_with_index do |l, i|
+        x[i], y[i] = l.split("\t")[0..1].map(&:to_f)
+      end
+
+      UnicodePlot.lineplot(x, y)
+    end
+
+    def lines(input_lines)
+      n_cols = input_lines[0].split("\t").size
+      cols = Array.new(n_cols){ [] }
+      input_lines.each_with_index do |row, i|
+        row.split("\t").each_with_index do |v, j|
+          cols[j][i] = v.to_f
+        end
+      end
+      require 'numo/narray'
+      pp Numo::DFloat.cast(cols)
+      plot = UnicodePlot.lineplot(cols[0], cols[1])
+      2.upto(n_cols - 1) do |i|
+        UnicodePlot.lineplot!(plot, cols[0], cols[i])
+      end
+      plot
+    end
   end
 end