plot -- ascii plot of numerical input data

gistfile1.rb

#!/usr/bin/env ruby

def usage(stdout = false)
	stream = stdout ? $stdout : $stderr

	bin = File.basename($0)
	indent = " " * (bin.length() + "Usage: ".length())

	stream.puts("Usage: #{bin} [--help|-h]")
	stream.puts(indent + " [--vertical]")
	stream.puts(indent + " [--width <columns>]")
	stream.puts(indent + " [--height <rows>]")
	stream.puts(indent + " [--label]")
	stream.puts <<eof
Plot data to a bar graph on the console.

Use the --vertical switch to plot vertical bars rather than horizontal ones. Use 
the --height option to specify a height when in vertical mode (defaults to the 
height of your terminal).

Use the --width option to specify a width (defaults to $COLUMNS).

Use the --label switch to enable labelling the bars in horizontal mode.

Standard input should be numeric data, one number per line.
eof
end

# duplicate stdin so we can get the terminal size without it getting our stdin 
# and so throwing errors
stdin = STDIN.dup
STDIN.reopen(STDOUT)

# get terminal size
terminalsize = %x(stty size).scan(/\d+/).map { |s| s.to_i }

# put it back how it was
STDIN.reopen(stdin)

# set defaults
nomoreoptions = false
direction = :horizontal
label = false
width = terminalsize[1]
if (width.nil?)
	width = 80
end
height = terminalsize[0]
if (height.nil?)
	height = 24
end

# handle arguments
while ($*.length() > 0)
	arg = $*.shift()
	if (arg == "--")
		nomoreoptions = true
		next
	end
	if (!nomoreoptions && arg[0,1] == "-")
		if (arg == "--help" || arg == "-h")
			usage(true)
			exit(0)
		elsif (arg == "--vertical")
			direction = :vertical
			next
		elsif (arg == "--label")
			label = true
			next
		elsif (arg == "--height")
			arg = $*.shift()
			if (arg.nil?)
				$stderr.puts("Expected a positive integer after the --height option")
			else
				arg = arg.to_i()
				if (arg > 0)
					height = arg
					next
				else
					$stderr.puts("Expected a positive integer after the --height option")
				end
			end
		elsif (arg == "--width")
			arg = $*.shift()
			if (arg.nil?)
				$stderr.puts("Expected a positive integer after the --width option")
			else
				arg = arg.to_i()
				if (arg > 0)
					width = arg
					next
				else
					$stderr.puts("Expected a positive integer after the --width option")
				end
			end
		else
			$stderr.puts("Unknown option \"#{arg}\"")
		end
	else
		$stderr.puts("Unexpected argument \"#{arg}\"")
	end

	# problem with arguments
	usage()
	exit(1)
end

# read stdin, treat each line as a float
data = $stdin.readlines()
data.map! { |datum| datum.to_f }
max = data.max()

if (direction == :horizontal)
	if (label)
		# get the longest string number when written as decimal
		stringnumbers = data.map { |datum| datum.to_s().length() }
		longestnumber = stringnumbers.max()
		usablewidth = width - longestnumber - 1
	else
		usablewidth = width
	end

	data.each do |datum|
		if (label)
			puts(datum.to_s().rjust(longestnumber) << " " << ("#" * (usablewidth * datum / max).round()))
		else
			puts("#" * (usablewidth * datum / max).round())
		end
	end
else
	# leave a row for the new prompt
	height -= 1

	# get the heights of each column
	bars = []
	for i in 0...width
		bars[i] = (height * data[(i * data.length() / width).round()] / max).round()
	end

	for i in 0...height
		for j in 0...width
			if (height - i > bars[j])
				$stdout.write(" ")
			else
				$stdout.write("#")
			end
		end
		$stdout.write($/)
	end
end