Class: AsciiChart

Inherits:
Object
  • Object
show all
Defined in:
lib/asciichart.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(rows = 20) ⇒ AsciiChart

Returns a new instance of AsciiChart.



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# File 'lib/asciichart.rb', line 6

def initialize(rows=20)
	@rows = rows
	@series = []
	@maxx = 0
	@miny = 0
	@maxy = 0
	@@colours = %w{red green blue}.map(&:to_sym)
end

Instance Attribute Details

#maxx ⇒ Object (readonly)

Returns the value of attribute maxx.



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# File 'lib/asciichart.rb', line 4

def maxx
  @maxx
end

#maxy ⇒ Object (readonly)

Returns the value of attribute maxy.



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# File 'lib/asciichart.rb', line 4

def maxy
  @maxy
end

#miny ⇒ Object (readonly)

Returns the value of attribute miny.



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# File 'lib/asciichart.rb', line 4

def miny
  @miny
end

#series ⇒ Object (readonly)

Returns the value of attribute series.



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# File 'lib/asciichart.rb', line 4

def series
  @series
end

Instance Method Details

#add_series(series, name = nil) ⇒ Object 



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# File 'lib/asciichart.rb', line 15

def add_series(series, name=nil)
	@series << {
		values: series, 
		colour: pick_colour(@series.length), 
		name: name ? name.capitalize : "Series #{@series.length}"
	}
	@miny = [series.min, @miny].min
	@maxy = [series.max, @maxy].max
	@maxx = [series.length, @maxx].max
end

#get_ascii_char(series, time, value_range) ⇒ Object 



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# File 'lib/asciichart.rb', line 64

def get_ascii_char(series, time, value_range)
	# returns an ascii character to represent the value-range for the given series at the given time
	# if the series does not have a high enough value at that time, we return ' '
	value = series[:values][time]
	if value and value >= value_range.max.to_f
		c = '#'
	elsif value and value > value_range.min.to_f
		c = '.'
	else
		c = ' '
	end
	c.send(series[:colour])
end

#num_series ⇒ Object 



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# File 'lib/asciichart.rb', line 26

def num_series
	@series.length
end

#pick_colour(index) ⇒ Object 



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# File 'lib/asciichart.rb', line 78

def pick_colour(index)
	@@colours[index % @@colours.length]
end

#render ⇒ Object 



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# File 'lib/asciichart.rb', line 30

def render
	# we need one column for each series up the maximum 
	# length of any one series, plus one for padding
	width = ((num_series + 2) * @maxx) + 2
	step = (@maxy - @miny) / @rows.to_f
	y_top = @maxy.to_f
	
	bitmap = '-' * (width + 2)
	bitmap += "\r\n|" + (' ' * width) + '|'

	@rows.times do
		bitmap += "\r\n|  "
		
		# loop on each distinct time/x value
		@maxx.times do |x|
			@series.each do |s|
				bitmap += get_ascii_char(s, x, (y_top - step)..y_top)
			end
			bitmap += '  '
		end
		bitmap += '|'
		y_top = (y_top - step).round(2)
	end
	bitmap += "\r\n" + ('-' * (width + 2))

	# the legend
	bitmap += "\r\n"
	@series.each do |s|
		bitmap += "\r\n" + s[:name].send(s[:colour])
	end

	puts bitmap
end