v0.2.5

* Use only comma separators
* A hyphen is indistinguishable from a minus sign
* Colon separators aren't as common as commas

.github/FUNDING.yml

@@ -0,0 +1,2 @@
+ko_fi: kojix2
+patreon: kojix2

Gemfile

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 source 'https://rubygems.org'
 
 # Specify your gem's dependencies in uplot.gemspec

README.md

@@ -1,7 +1,9 @@
-# Uplot
+# uplot
 
 [![Build Status](https://travis-ci.com/kojix2/uplot.svg?branch=master)](https://travis-ci.com/kojix2/uplot)
 [![Gem Version](https://badge.fury.io/rb/u-plot.svg)](https://badge.fury.io/rb/u-plot)
+[![Docs Latest](https://img.shields.io/badge/docs-latest-blue.svg)](https://rubydoc.info/gems/u-plot)
+[![The MIT License](https://img.shields.io/badge/license-MIT-blue.svg)](LICENSE.txt)
 
 Create ASCII charts on the terminal with data from standard streams in the pipeline. 
 
@@ -17,39 +19,29 @@ gem install u-plot
 
 ## Usage
 
-### histogram
+**histogram**
 
 ```sh
 ruby -r numo/narray -e "puts Numo::DFloat.new(1000).rand_norm.to_a" \
   | uplot hist --nbins 15
 ```
 
-```
-                ┌                                        ┐ 
-   [-4.5, -4.0) ┤ 1                                        
-   [-4.0, -3.5) ┤ 0                                        
-   [-3.5, -3.0) ┤ 1                                        
-   [-3.0, -2.5) ┤▇▇ 9                                      
-   [-2.5, -2.0) ┤▇▇▇ 15                                    
-   [-2.0, -1.5) ┤▇▇▇▇▇▇▇▇▇ 50                              
-   [-1.5, -1.0) ┤▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ 97                     
-   [-1.0, -0.5) ┤▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ 154          
-   [-0.5,  0.0) ┤▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ 193   
-   [ 0.0,  0.5) ┤▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ 165        
-   [ 0.5,  1.0) ┤▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ 152          
-   [ 1.0,  1.5) ┤▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ 86                       
-   [ 1.5,  2.0) ┤▇▇▇▇▇▇▇▇▇ 51                              
-   [ 2.0,  2.5) ┤▇▇▇▇ 21                                   
-   [ 2.5,  3.0) ┤▇ 3                                       
-   [ 3.0,  3.5) ┤ 2                                        
-                └                                        ┘ 
-                                Frequency
+<img src="https://i.imgur.com/wpsoGJq.png" width="75%" height="75%"></img>
+
+**scatter**
+
+```sh
+wget https://raw.githubusercontent.com/uiuc-cse/data-fa14/gh-pages/data/iris.csv -qO - \
+ | cut -f1-4 -d, \
+ | uplot scatter -H -d, -t IRIS -m 10
 ```
 
 ## Development
 
 ## Contributing
 
+Bug reports and pull requests are welcome on GitHub at [https://github.com/kojix2/uplot](https://github.com/kojix2/uplot).
+
 ## License
 
 The gem is available as open source under the terms of the [MIT License](https://opensource.org/licenses/MIT).

Rakefile

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'bundler/gem_tasks'
 require 'rake/testtask'
 

exe/uplot

@@ -1,5 +1,6 @@
 #!/usr/bin/env ruby
+# frozen_string_literal: true
 
 require 'uplot'
 
-Uplot::Command.new(ARGV).run
+Uplot::Command.new.run

lib/uplot.rb

@@ -1,6 +1,10 @@
+# frozen_string_literal: true
+
 require 'unicode_plot'
 require 'uplot/version'
-require 'uplot/command.rb'
+require 'uplot/preprocessing'
+require 'uplot/plot'
+require 'uplot/command'
 
 module Uplot
 end

lib/uplot/command.rb

@@ -1,269 +1,83 @@
-require 'optparse'
-require 'csv'
-require 'unicode_plot'
+# frozen_string_literal: true
+
+require_relative 'preprocessing'
+require_relative 'command/parser'
 
 module Uplot
+  Data = Struct.new(:headers, :series)
+
   class Command
-    def initialize(argv)
-      @params    = {}
-      @ptype     = nil
-      @headers   = nil
-      @delimiter = "\t"
-      @transpose = false
-      @output    = false
-      @count     = false
-      @fmt       = 'xyy'
-      @debug     = false
-      parse_options(argv)
-    end
+    attr_accessor :params
+    attr_reader :raw_inputs, :data, :fmt, :parser
 
-    def create_parser
-      OptionParser.new
-                  .on('-o', '--output', TrueClass)     { |v| @output = v }
-                  .on('-d', '--delimiter VAL', String) { |v| @delimiter = v }
-                  .on('-H', '--headers', TrueClass)    { |v| @headers = v }
-                  .on('-T', '--transpose', TrueClass)  { |v| @transpose = v }
-                  .on('-t', '--title VAL', String)     { |v| @params[:title] = v }
-                  .on('-w', '--width VAL', Numeric)    { |v| @params[:width] = v }
-                  .on('-h', '--height VAL', Numeric)   { |v| @params[:height] = v }
-                  .on('-b', '--border VAL', Numeric)   { |v| @params[:border] = v }
-                  .on('-m', '--margin VAL', Numeric)   { |v| @params[:margin] = v }
-                  .on('-p', '--padding VAL', Numeric)  { |v| @params[:padding] = v }
-                  .on('-c', '--color VAL', String)     { |v| @params[:color] = v.to_sym }
-                  .on('-x', '--xlabel VAL', String)    { |v| @params[:xlabel] = v }
-                  .on('-y', '--ylabel VAL', String)    { |v| @params[:ylabel] = v }
-                  .on('-l', '--labels', TrueClass)     { |v| @params[:labels] = v }
-                  .on('--fmt VAL', String)             { |v| @fmt = v }
-                  .on('--debug', TrueClass)            { |v| @debug = v }
-    end
+    def initialize
+      @params = Params.new
 
-    def parse_options(argv)
-      main_parser          = create_parser
-      parsers              = Hash.new { |h, k| h[k] = create_parser }
-      parsers['barplot']   = parsers['bar']
-                             .on('--symbol VAL', String) { |v| @params[:symbol] = v }
-                             .on('--xscale VAL', String) { |v| @params[:xscale] = v }
-                             .on('--count', TrueClass)   { |v| @count = v }
-      parsers['count']     = parsers['c'] # barplot -c
-                             .on('--symbol VAL', String) { |v| @params[:symbol] = v }
-      parsers['histogram'] = parsers['hist']
-                             .on('-n', '--nbins VAL', Numeric) { |v| @params[:nbins] = v }
-                             .on('--closed VAL', String) { |v| @params[:closed] = v }
-                             .on('--symbol VAL', String) { |v| @params[:symbol] = v }
-      parsers['lineplot']  = parsers['line']
-                             .on('--canvas VAL', String) { |v| @params[:canvas] = v }
-                             .on('--xlim VAL', String)   { |v| @params[:xlim] = get_lim(v) }
-                             .on('--ylim VAL', String)   { |v| @params[:ylim] = get_lim(v) }
-      parsers['lineplots'] = parsers['lines']
-                             .on('--canvas VAL', String) { |v| @params[:canvas] = v }
-                             .on('--xlim VAL', String)   { |v| @params[:xlim] = get_lim(v) }
-                             .on('--ylim VAL', String)   { |v| @params[:ylim] = get_lim(v) }
-      parsers['scatter']   = parsers['s']
-                             .on('--canvas VAL', String) { |v| @params[:canvas] = v }
-                             .on('--xlim VAL', String)   { |v| @params[:xlim] = get_lim(v) }
-                             .on('--ylim VAL', String)   { |v| @params[:ylim] = get_lim(v) }
-      parsers['density']   = parsers['d']
-                             .on('--grid', TrueClass)    { |v| @params[:grid] = v }
-                             .on('--xlim VAL', String)   { |v| @params[:xlim] = get_lim(v) }
-                             .on('--ylim VAL', String)   { |v| @params[:ylim] = get_lim(v) }
-      parsers['boxplot']   = parsers['box']
-                             .on('--xlim VAL', String)   { |v| @params[:xlim] = get_lim(v) }
-      parsers.default      = nil
+      @raw_inputs = []
 
-      main_parser.banner = <<~MSG
-        Program: uplot (Tools for plotting on the terminal)
-        Version: #{Uplot::VERSION} (using unicode_plot #{UnicodePlot::VERSION})
-
-        Usage:   uplot <command> [options]
-
-        Command: #{parsers.keys.join(' ')}
-
-        Options:
-      MSG
-
-      begin
-        main_parser.order!(argv)
-      rescue OptionParser::ParseError => e
-        warn "uplot: #{e.message}"
-        exit 1
-      end
-
-      @ptype = argv.shift
-
-      unless parsers.has_key?(@ptype)
-        if @ptype.nil?
-          warn main_parser.help
-        else
-          warn "uplot: unrecognized command '#{@ptype}'"
-        end
-        exit 1
-      end
-      parser = parsers[@ptype]
-
-      begin
-        parser.parse!(argv) unless argv.empty?
-      rescue OptionParser::ParseError => e
-        warn "uplot: #{e.message}"
-        exit 1
-      end
+      @parser = Parser.new
     end
 
     def run
+      parser.parse_options
+      command   = parser.command
+      params    = parser.params
+      delimiter = parser.delimiter
+      transpose = parser.transpose
+      headers   = parser.headers
+      pass      = parser.pass
+      output    = parser.output
+      fmt       = parser.fmt
+      @debug    = parser.debug
+
+      if command == :colors
+        Plot.colors
+        exit
+      end
+
       # Sometimes the input file does not end with a newline code.
-      while input = Kernel.gets(nil)
+      while (input = Kernel.gets(nil))
         input.freeze
-        data, headers = preprocess(input)
-        pp input: input, data: data, headers: headers if @debug
-        case @ptype
-        when 'bar', 'barplot'
-          barplot(data, headers)
-        when 'count', 'c'
-          @count = true
-          barplot(data, headers)
-        when 'hist', 'histogram'
-          histogram(data, headers)
-        when 'line', 'lineplot'
-          line(data, headers)
-        when 'lines', 'lineplots'
-          lines(data, headers)
-        when 'scatter', 'scatterplot'
-          scatter(data, headers)
-        when 'density'
-          density(data, headers)
-        when 'box', 'boxplot'
-          boxplot(data, headers)
-        end.render($stderr)
+        @raw_inputs << input
+        @data = Preprocessing.input(input, delimiter, headers, transpose)
+        pp @data if @debug
+        plot = case command
+               when :bar, :barplot
+                 Plot.barplot(data, params)
+               when :count, :c
+                 Plot.barplot(data, params, count: true)
+               when :hist, :histogram
+                 Plot.histogram(data, params)
+               when :line, :lineplot
+                 Plot.line(data, params)
+               when :lines, :lineplots
+                 Plot.lines(data, params, fmt)
+               when :scatter, :s
+                 Plot.scatter(data, params, fmt)
+               when :density, :d
+                 Plot.density(data, params, fmt)
+               when :box, :boxplot
+                 Plot.boxplot(data, params)
+               else
+                 raise "unrecognized plot_type: #{command}"
+               end
 
-        print input if @output
-      end
-    end
-
-    # https://stackoverflow.com/q/26016632
-    def transpose2(arr) # Should be renamed
-      Array.new(arr.map(&:length).max) { |i| arr.map { |e| e[i] } }
-    end
-
-    def preprocess(input)
-      data = CSV.parse(input, col_sep: @delimiter)
-      data.delete([]) # Remove blank lines.
-      data.delete_if { |i| i.all? nil } # Room for improvement.
-      p parsed_csv: data if @debug
-      headers = nil
-      if @transpose
-        if @headers
-          headers = []
-          # each but destructive like map
-          data.each { |series| headers << series.shift }
+        if output.is_a?(IO)
+          plot.render(output)
+        else
+          File.open(output, 'w') do |f|
+            plot.render(f)
+          end
+        end
+
+        if pass.is_a?(IO)
+          print input
+        elsif pass
+          File.open(pass, 'w') do |f|
+            f.print(input)
+          end
         end
-      else
-        headers = data.shift if @headers
-        data = transpose2(data)
       end
-      [data, headers]
-    end
-
-    def preprocess_count(data)
-      if Enumerable.method_defined? :tally
-        data[0].tally
-      else # https://github.com/marcandre/backports tally
-        data[0].each_with_object(Hash.new(0)) { |item, res| res[item] += 1 }
-               .tap { |h| h.default = nil }
-      end.sort { |a, b| a[1] <=> b[1] }.reverse.transpose
-    end
-
-    def barplot(data, headers)
-      data = preprocess_count(data) if @count
-      @params[:title] ||= headers[1] if headers
-      UnicodePlot.barplot(data[0], data[1].map(&:to_f), **@params)
-    end
-
-    def histogram(data, headers)
-      @params[:title] ||= headers[0] if headers # labels?
-      series = data[0].map(&:to_f)
-      UnicodePlot.histogram(series, **@params.compact)
-    end
-
-    def get_lim(str)
-      str.split(/-|:|\.\./)[0..1].map(&:to_f)
-    end
-
-    def line(data, headers)
-      if data.size == 1
-        @params[:ylabel] ||= headers[0] if headers
-        y = data[0].map(&:to_f)
-        UnicodePlot.lineplot(y, **@params.compact)
-      else
-        @params[:xlabel] ||= headers[0] if headers
-        @params[:ylabel] ||= headers[1] if headers
-        x = data[0].map(&:to_f)
-        y = data[1].map(&:to_f)
-        UnicodePlot.lineplot(x, y, **@params.compact)
-      end
-    end
-
-    def get_method2(method1)
-      (method1.to_s + '!').to_sym
-    end
-
-    def xyy_plot(data, headers, method1) # improve method name
-      method2 = get_method2(method1)
-      data.map! { |series| series.map(&:to_f) }
-      @params[:name] ||= headers[1] if headers
-      @params[:xlabel] ||= headers[0] if headers
-      @params[:ylim] ||= data[1..-1].flatten.minmax # need?
-      plot = UnicodePlot.public_send(method1, data[0], data[1], **@params.compact)
-      2.upto(data.size - 1) do |i|
-        UnicodePlot.public_send(method2, plot, data[0], data[i], name: headers[i])
-      end
-      plot
-    end
-
-    def xyxy_plot(data, headers, method1) # improve method name
-      method2 = get_method2(method1)
-      data.map! { |series| series.map(&:to_f) }
-      data = data.each_slice(2).to_a
-      @params[:name] ||= headers[0] if headers
-      @params[:xlim] = data.map(&:first).flatten.minmax
-      @params[:ylim] = data.map(&:last).flatten.minmax
-      x1, y1 = data.shift
-      plot = UnicodePlot.public_send(method1, x1, y1, **@params.compact)
-      data.each_with_index do |(xi, yi), i|
-        UnicodePlot.public_send(method2, plot, xi, yi, name: headers[(i + 1) * 2])
-      end
-      plot
-    end
-
-    def lines(data, headers)
-      case @fmt
-      when 'xyy'
-        xyy_plot(data, headers, :lineplot)
-      when 'xyxy'
-        xyxy_plot(data, headers, :lineplot)
-      end
-    end
-
-    def scatter(data, headers)
-      case @fmt
-      when 'xyy'
-        xyy_plot(data, headers, :scatterplot)
-      when 'xyxy'
-        xyxy_plot(data, headers, :scatterplot)
-      end
-    end
-
-    def density(data, headers)
-      case @fmt
-      when 'xyy'
-        xyy_plot(data, headers, :densityplot)
-      when 'xyxy'
-        xyxy_plot(data, headers, :densityplot)
-      end
-    end
-
-    def boxplot(data, headers)
-      headers ||= (1..data.size).map(&:to_s)
-      data.map! { |series| series.map(&:to_f) }
-      UnicodePlot.boxplot(headers, data, **@params.compact)
     end
   end
 end

lib/uplot/command/params.rb

@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+
+module Uplot
+  class Command
+    Params = Struct.new(
+      # Sort me!
+      :title,
+      :width,
+      :height,
+      :border,
+      :margin,
+      :padding,
+      :color,
+      :xlabel,
+      :ylabel,
+      :labels,
+      :symbol,
+      :xscale,
+      :nbins,
+      :closed,
+      :canvas,
+      :xlim,
+      :ylim,
+      :grid,
+      :name
+    ) do
+      def to_hc
+        to_h.compact
+      end
+    end
+  end
+end

lib/uplot/command/parser.rb

@@ -0,0 +1,224 @@
+# frozen_string_literal: true
+
+require 'optparse'
+require_relative 'params'
+
+module Uplot
+  class Command
+    class Parser
+      attr_reader :command, :params,
+                  :delimiter, :transpose, :headers, :pass, :output, :fmt, :debug
+
+      def initialize
+        @command = nil
+        @params = Params.new
+
+        @delimiter  = "\t"
+        @transpose  = false
+        @headers    = nil
+        @pass       = false
+        @output     = $stderr
+        @fmt        = 'xyy'
+        @debug      = false
+      end
+
+      def create_default_parser
+        OptionParser.new do |opt|
+          opt.program_name = 'uplot'
+          opt.version = Uplot::VERSION
+          opt.on('-O', '--pass [VAL]', 'file to output standard input data to [stdout]') do |v|
+            @pass = v || $stdout
+          end
+          opt.on('-o', '--output VAL', 'file to output results to [stderr]') do |v|
+            @output = v
+          end
+          opt.on('-d', '--delimiter VAL', String, 'use DELIM instead of TAB for field delimiter') do |v|
+            @delimiter = v
+          end
+          opt.on('-H', '--headers', TrueClass, 'specify that the input has header row') do |v|
+            @headers = v
+          end
+          opt.on('-T', '--transpose', TrueClass) do |v|
+            @transpose = v
+          end
+          opt.on('-t', '--title VAL', String, 'print string on the top of plot') do |v|
+            params.title = v
+          end
+          opt.on('-x', '--xlabel VAL', String, 'print string on the bottom of the plot') do |v|
+            params.xlabel = v
+          end
+          opt.on('-y', '--ylabel VAL', String, 'print string on the far left of the plot') do |v|
+            params.ylabel = v
+          end
+          opt.on('-w', '--width VAL', Integer, 'number of characters per row') do |v|
+            params.width = v
+          end
+          opt.on('-h', '--height VAL', Numeric, 'number of rows') do |v|
+            params.height = v
+          end
+          opt.on('-b', '--border VAL', String, 'specify the style of the bounding box') do |v|
+            params.border = v.to_sym
+          end
+          opt.on('-m', '--margin VAL', Numeric, 'number of spaces to the left of the plot') do |v|
+            params.margin = v
+          end
+          opt.on('-p', '--padding VAL', Numeric, 'space of the left and right of the plot') do |v|
+            params.padding = v
+          end
+          opt.on('-c', '--color VAL', String, 'color of the drawing') do |v|
+            params.color = v =~ /\A[0-9]+\z/ ? v.to_i : v.to_sym
+          end
+          opt.on('--[no-]labels', TrueClass, 'hide the labels') do |v|
+            params.labels = v
+          end
+          opt.on('--fmt VAL', String, 'xyxy : header is like x1, y1, x2, y2, x3, y3...', 'xyy  : header is like x, y1, y2, y2, y3...') do |v|
+            @fmt = v
+          end
+          opt.on('--debug', TrueClass) do |v|
+            @debug = v
+          end
+          yield opt if block_given?
+        end
+      end
+
+      def main_parser
+        @main_parser ||= create_default_parser do |main_parser|
+          # Usage and help messages
+          main_parser.banner = \
+            <<~MSG
+              Program: uplot (Tools for plotting on the terminal)
+              Version: #{Uplot::VERSION} (using unicode_plot #{UnicodePlot::VERSION})
+
+              Usage:   uplot <command> [options]
+
+              Command: barplot    bar
+                       histogram  hist
+                       lineplot   line
+                       scatter    s
+                       density    d
+                       boxplot    box
+                       colors
+
+              Options:
+            MSG
+        end
+      end
+
+      def sub_parser
+        @sub_parser ||= create_default_parser do |parser|
+          parser.banner = <<~MSG
+            Usage: uplot #{command} [options]
+
+            Options:
+          MSG
+
+          case command
+          when nil
+            warn main_parser.help
+            exit 1
+
+          when :barplot, :bar
+            parser.on('--symbol VAL', String) do |v|
+              params.symbol = v
+            end
+            parser.on('--xscale VAL', String) do |v|
+              params.xscale = v
+            end
+
+          when :count, :c
+            parser.on('--symbol VAL', String) do |v|
+              params.symbol = v
+            end
+
+          when :histogram, :hist
+            parser.on('-n', '--nbins VAL', Numeric) do |v|
+              params.nbins = v
+            end
+            parser.on('--closed VAL', String) do |v|
+              params.closed = v
+            end
+            parser.on('--symbol VAL', String) do |v|
+              params.symbol = v
+            end
+
+          when :lineplot, :line
+            parser.on('--canvas VAL', String) do |v|
+              params.canvas = v
+            end
+            parser.on('--xlim VAL', Array) do |v|
+              params.xlim = v.take(2)
+            end
+            parser.on('--ylim VAL', Array) do |v|
+              params.ylim = v.take(2)
+            end
+
+          when :lineplots, :lines
+            parser.on('--canvas VAL', String) do |v|
+              params.canvas = v
+            end
+            parser.on('--xlim VAL', Array) do |v|
+              params.xlim = v.take(2)
+            end
+            parser.on('--ylim VAL', Array) do |v|
+              params.ylim = v.take(2)
+            end
+
+          when :scatter, :s
+            parser.on('--canvas VAL', String) do |v|
+              params.canvas = v
+            end
+            parser.on('--xlim VAL', Array) do |v|
+              params.xlim = v.take(2)
+            end
+            parser.on('--ylim VAL', Array) do |v|
+              params.ylim = v.take(2)
+            end
+
+          when :density, :d
+            parser.on('--grid', TrueClass) do |v|
+              params.grid = v
+            end
+            parser.on('--xlim VAL', Array) do |v|
+              params.xlim = v.take(2)
+            end
+            parser.on('--ylim VAL', Array) do |v|
+              params.ylim = v.take(2)
+            end
+
+          when :boxplot, :box
+            parser.on('--xlim VAL', Array) do |v|
+              params.xlim = v.take(2)
+            end
+
+          when :colors
+            parser.on('-n', '--names', TrueClass) do |v|
+              @color_names = v
+            end
+
+          else
+            warn "uplot: unrecognized command '#{command}'"
+            exit 1
+          end
+        end
+      end
+
+      def parse_options(argv = ARGV)
+        begin
+          main_parser.order!(argv)
+        rescue OptionParser::ParseError => e
+          warn "uplot: #{e.message}"
+          exit 1
+        end
+
+        @command = argv.shift&.to_sym
+
+        begin
+          sub_parser.parse!(argv)
+        rescue OptionParser::ParseError => e
+          warn "uplot: #{e.message}"
+          exit 1
+        end
+      end
+    end
+  end
+end

lib/uplot/plot.rb

@@ -0,0 +1,159 @@
+# frozen_string_literal: true
+
+require 'unicode_plot'
+
+module Uplot
+  # plotting functions.
+  module Plot
+    module_function
+
+    def barplot(data, params, count: false)
+      headers = data.headers
+      series = data.series
+      if count
+        series = Preprocessing.count(series[0])
+        params.title = headers[0] if headers
+      end
+      params.title ||= headers[1] if headers
+      labels = series[0]
+      values = series[1].map(&:to_f)
+      UnicodePlot.barplot(labels, values, **params.to_hc)
+    end
+
+    def histogram(data, params)
+      headers = data.headers
+      series = data.series
+      params.title ||= data.headers[0] if headers
+      values = series[0].map(&:to_f)
+      UnicodePlot.histogram(values, **params.to_hc)
+    end
+
+    def line(data, params)
+      headers = data.headers
+      series = data.series
+      if series.size == 1
+        # If there is only one series, it is assumed to be sequential data.
+        params.ylabel ||= headers[0] if headers
+        y = series[0].map(&:to_f)
+        UnicodePlot.lineplot(y, **params.to_hc)
+      else
+        # If there are 2 or more series,
+        # assume that the first 2 series are the x and y series respectively.
+        if headers
+          params.xlabel ||= headers[0]
+          params.ylabel ||= headers[1]
+        end
+        x = series[0].map(&:to_f)
+        y = series[1].map(&:to_f)
+        UnicodePlot.lineplot(x, y, **params.to_hc)
+      end
+    end
+
+    def get_method2(method1)
+      (method1.to_s + '!').to_sym
+    end
+
+    def xyy_plot(data, method1, params)
+      headers = data.headers
+      series = data.series
+      method2 = get_method2(method1)
+      series.map! { |s| s.map(&:to_f) }
+      if headers
+        params.name   ||= headers[1]
+        params.xlabel ||= headers[0]
+      end
+      params.ylim ||= series[1..-1].flatten.minmax # why need?
+      plot = UnicodePlot.public_send(method1, series[0], series[1], **params.to_hc)
+      2.upto(series.size - 1) do |i|
+        UnicodePlot.public_send(method2, plot, series[0], series[i], name: headers&.[](i))
+      end
+      plot
+    end
+
+    def xyxy_plot(data, method1, params)
+      headers = data.headers
+      series = data.series
+      method2 = get_method2(method1)
+      series.map! { |s| s.map(&:to_f) }
+      series = series.each_slice(2).to_a
+      params.name ||= headers[0] if headers
+      params.xlim = series.map(&:first).flatten.minmax # why need?
+      params.ylim = series.map(&:last).flatten.minmax  # why need?
+      x1, y1 = series.shift
+      plot = UnicodePlot.public_send(method1, x1, y1, **params.to_hc)
+      series.each_with_index do |(xi, yi), i|
+        UnicodePlot.public_send(method2, plot, xi, yi, name: headers&.[]((i + 1) * 2))
+      end
+      plot
+    end
+
+    def lines(data, params, fmt = 'xyy')
+      check_series_size(data, fmt)
+      case fmt
+      when 'xyy'
+        xyy_plot(data, :lineplot, params)
+      when 'xyxy'
+        xyxy_plot(data, :lineplot, params)
+      end
+    end
+
+    def scatter(data, params, fmt = 'xyy')
+      check_series_size(data, fmt)
+      case fmt
+      when 'xyy'
+        xyy_plot(data, :scatterplot, params)
+      when 'xyxy'
+        xyxy_plot(data, :scatterplot, params)
+      end
+    end
+
+    def density(data, params, fmt = 'xyy')
+      check_series_size(data, fmt)
+      case fmt
+      when 'xyy'
+        xyy_plot(data, :densityplot, params)
+      when 'xyxy'
+        xyxy_plot(data, :densityplot, params)
+      end
+    end
+
+    def boxplot(data, params)
+      headers = data.headers
+      series = data.series
+      headers ||= (1..series.size).map(&:to_s)
+      series.map! { |s| s.map(&:to_f) }
+      UnicodePlot.boxplot(headers, series, **params.to_hc)
+    end
+
+    def colors
+      UnicodePlot::StyledPrinter::TEXT_COLORS.each do |k, v|
+        print v
+        print k
+        print "\t"
+        print '  ●'
+        print "\033[0m"
+        print "\t"
+      end
+      puts
+    end
+
+    def check_series_size(data, fmt)
+      series = data.series
+      if series.size == 1
+        warn 'uplot: There is only one series of input data. Please check the delimiter.'
+        warn ''
+        warn "  Headers: \e[35m#{data.headers.inspect}\e[0m"
+        warn "  The first item is: \e[35m\"#{series[0][0]}\"\e[0m"
+        warn "  The last item is : \e[35m\"#{series[0][-1]}\"\e[0m"
+        exit 1
+      end
+      if fmt == 'xyxy' && series.size.odd?
+        warn 'uplot: In the xyxy format, the number of series must be even.'
+        warn ''
+        warn "  Number of series: \e[35m#{series.size}\e[0m"
+        warn "  Headers: \e[35m#{data.headers.inspect}\e[0m"
+        exit 1
+      end
+    end
+  end
+end

lib/uplot/preprocessing.rb

@@ -0,0 +1,88 @@
+# frozen_string_literal: true
+
+require 'csv'
+
+module Uplot
+  module Preprocessing
+    module_function
+
+    def input(input, delimiter, headers, transpose)
+      arr = parse_as_csv(input, delimiter)
+      headers = get_headers(arr, headers, transpose)
+      series = get_series(arr, headers, transpose)
+      if headers.nil?
+        Data.new(headers, series)
+      else
+        if headers.include?(nil)
+          warn "\e[35mHeaders contains nil in it.\e[0m"
+        elsif headers.include? ''
+          warn "\e[35mHeaders contains \"\" in it.\e[0m"
+        end
+        h_size = headers.size
+        s_size = series.size
+        if h_size == s_size
+          Data.new(headers, series)
+        elsif h_size > s_size
+          warn "\e[35mThe number of headers is greater than the number of series.\e[0m"
+          exit 1
+        elsif h_size < s_size
+          warn "\e[35mThe number of headers is less than the number of series.\e[0m"
+          exit 1
+        end
+      end
+    end
+
+    def parse_as_csv(input, delimiter)
+      CSV.parse(input, col_sep: delimiter)
+         .delete_if do |i|
+           i == [] or i.all? nil
+         end
+    end
+
+    # Transpose different sized ruby arrays
+    # https://stackoverflow.com/q/26016632
+    def transpose2(arr)
+      Array.new(arr.map(&:length).max) { |i| arr.map { |e| e[i] } }
+    end
+
+    def get_headers(arr, headers, transpose)
+      if headers
+        if transpose
+          arr.map(&:first)
+        else
+          arr[0]
+        end
+      end
+    end
+
+    def get_series(arr, headers, transpose)
+      if transpose
+        if headers
+          arr.map { |row| row[1..-1] }
+        else
+          arr
+        end
+      else
+        if headers
+          transpose2(arr[1..-1])
+        else
+          transpose2(arr)
+        end
+      end
+    end
+
+    def count(arr)
+      # tally was added in Ruby 2.7
+      if Enumerable.method_defined? :tally
+        arr.tally
+      else
+        # https://github.com/marcandre/backports
+        arr.each_with_object(Hash.new(0)) { |item, res| res[item] += 1 }
+           .tap { |h| h.default = nil }
+      end
+        .sort { |a, b| a[1] <=> b[1] }
+        .reverse
+        .transpose
+    end
+  end
+end

lib/uplot/version.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Uplot
-  VERSION = '0.1.4'.freeze
+  VERSION = '0.2.5'
 end

test/test_helper.rb

@@ -1,4 +1,8 @@
-$LOAD_PATH.unshift File.expand_path('../lib', __dir__)
+# frozen_string_literal: true
+
+require 'simplecov'
+SimpleCov.start
+
 require 'uplot'
 
 require 'test/unit'

test/uplot/command_test.rb

@@ -0,0 +1,6 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper.rb'
+
+class UplotCommandTest < Test::Unit::TestCase
+end

test/uplot/plot_test.rb

@@ -0,0 +1,6 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper.rb'
+
+class UplotPlotTest < Test::Unit::TestCase
+end

test/uplot/preprocessing_test.rb

@@ -0,0 +1,132 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper.rb'
+
+class UplotPreprocessingTest < Test::Unit::TestCase
+  def setup
+    @m = Uplot::Preprocessing
+  end
+
+  test :transpose2 do
+    n = nil
+
+    assert_equal([[1, 2, 3],
+                  [4, 5, 6],
+                  [7, 8, 9]], @m.transpose2([[1, 4, 7],
+                                             [2, 5, 8],
+                                             [3, 6, 9]]))
+    assert_equal([[1, 2, 3],
+                  [4, 5, n],
+                  [6, n, n]], @m.transpose2([[1, 4, 6],
+                                             [2, 5],
+                                             [3]]))
+    assert_equal([[1, 2, 3],
+                  [n, 4, 5],
+                  [n, n, 6]], @m.transpose2([[1],
+                                             [2, 4],
+                                             [3, 5, 6]]))
+  end
+
+  test :get_headers do
+    assert_equal([1, 4, 7], @m.get_headers([[1, 2, 3],
+                                            [4, 5, 6],
+                                            [7, 8, 9]], true, true))
+
+    assert_equal([1, 2, 3], @m.get_headers([[1, 4, 6],
+                                            [2, 5],
+                                            [3]], true, true))
+
+    assert_equal([1, 2, 3], @m.get_headers([[1],
+                                            [2, 4],
+                                            [3, 5, 6]], true, true))
+
+    assert_equal([1, 2, 3], @m.get_headers([[1, 2, 3],
+                                            [4, 5, 6],
+                                            [7, 8, 9]], true, false))
+
+    assert_equal([1, 4, 6], @m.get_headers([[1, 4, 6],
+                                            [2, 5],
+                                            [3]], true, false))
+
+    assert_equal([1], @m.get_headers([[1],
+                                      [2, 4],
+                                      [3, 5, 6]], true, false))
+
+    assert_equal(nil, @m.get_headers([[1, 2, 3],
+                                      [4, 5, 6],
+                                      [7, 8, 9]], false, true))
+
+    assert_equal(nil, @m.get_headers([[1, 2, 3],
+                                      [4, 5, 6],
+                                      [7, 8, 9]], false, false))
+  end
+
+  test :get_series do
+    n = nil
+
+    assert_equal([[2, 3], [5, 6], [8, 9]], @m.get_series([[1, 2, 3],
+                                                          [4, 5, 6],
+                                                          [7, 8, 9]], true, true))
+
+    assert_equal([[4, 6], [5], []], @m.get_series([[1, 4, 6],
+                                                   [2, 5],
+                                                   [3]], true, true))
+
+    assert_equal([[], [4], [5, 6]], @m.get_series([[1],
+                                                   [2, 4],
+                                                   [3, 5, 6]], true, true))
+
+    assert_equal([[4, 7], [5, 8], [6, 9]], @m.get_series([[1, 2, 3],
+                                                          [4, 5, 6],
+                                                          [7, 8, 9]], true, false))
+
+    assert_equal([[2, 3], [5, nil]], @m.get_series([[1, 4, 6],
+                                                    [2, 5],
+                                                    [3]], true, false))
+
+    assert_equal([[2, 3], [4, 5], [nil, 6]], @m.get_series([[1],
+                                                            [2, 4],
+                                                            [3, 5, 6]], true, false))
+
+    assert_equal([[1, 2, 3],
+                  [4, 5, 6],
+                  [7, 8, 9]], @m.get_series([[1, 2, 3],
+                                             [4, 5, 6],
+                                             [7, 8, 9]], false, true))
+
+    assert_equal([[1, 4, 6],
+                  [2, 5],
+                  [3]], @m.get_series([[1, 4, 6],
+                                       [2, 5],
+                                       [3]], false, true))
+
+    assert_equal([[1],
+                  [2, 4],
+                  [3, 5, 6]], @m.get_series([[1],
+                                             [2, 4],
+                                             [3, 5, 6]], false, true))
+
+    assert_equal([[1, 4, 7],
+                  [2, 5, 8],
+                  [3, 6, 9]], @m.get_series([[1, 2, 3],
+                                             [4, 5, 6],
+                                             [7, 8, 9]], false, false))
+
+    assert_equal([[1, 2, 3],
+                  [4, 5, n],
+                  [6, n, n]], @m.get_series([[1, 4, 6],
+                                             [2, 5],
+                                             [3]], false, false))
+
+    assert_equal([[1, 2, 3],
+                  [n, 4, 5],
+                  [n, n, 6]], @m.get_series([[1],
+                                             [2, 4],
+                                             [3, 5, 6]], false, false))
+  end
+
+  test :count do
+    assert_equal([%i[a b c], [3, 2, 1]], @m.count(%i[a a a b b c]))
+    assert_equal([%i[c b a], [3, 2, 1]], @m.count(%i[a b b c c c]))
+  end
+end

test/uplot_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class UplotTest < Test::Unit::TestCase

uplot.gemspec

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative 'lib/uplot/version'
 
 Gem::Specification.new do |spec|
@@ -13,7 +15,7 @@ Gem::Specification.new do |spec|
   MSG
   spec.homepage      = 'https://github.com/kojix2/uplot'
   spec.license       = 'MIT'
-  spec.required_ruby_version = Gem::Requirement.new('>= 2.3.0')
+  spec.required_ruby_version = Gem::Requirement.new('>= 2.4.0')
 
   spec.files         = Dir['*.{md,txt}', '{lib,exe}/**/*']
   spec.bindir        = 'exe'
@@ -24,5 +26,6 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'bundler'
   spec.add_development_dependency 'rake'
   spec.add_development_dependency 'rubocop'
+  spec.add_development_dependency 'simplecov'
   spec.add_development_dependency 'test-unit'
 end