pygal/svg/charts/schedule.py

#!python
import re

from dateutil.parser import parse
from dateutil.relativedelta import relativedelta
from lxml import etree

from svg.charts.graph import Graph
from util import grouper, date_range, divide_timedelta_float, TimeScale

__all__ = ('Schedule')

class Schedule(Graph):
	"""
	    # === For creating SVG plots of scalar temporal data
	
	= Synopsis
	
	  require 'SVG/Graph/Schedule'
	
	  # Data sets are label, start, end tripples.
	  data1 = [
		"Housesitting", "6/17/04", "6/19/04", 
		"Summer Session", "6/15/04", "8/15/04",
	  ]
	
	  graph = SVG::Graph::Schedule.new( {
		:width => 640,
		:height => 480,
		:graph_title => title,
		:show_graph_title => true,
		:no_css => true,
		:scale_x_integers => true,
		:scale_y_integers => true,
		:min_x_value => 0,
		:min_y_value => 0,
		:show_data_labels => true,
		:show_x_guidelines => true,
		:show_x_title => true,
		:x_title => "Time",
		:stagger_x_labels => true,
		:stagger_y_labels => true,
		:x_label_format => "%m/%d/%y",
	  })
	  
	  graph.add_data({
	   :data => data1,
		 :title => 'Data',
	  })
	
	  print graph.burn()
	
	= Description
	
	Produces a graph of temporal scalar data.
	
	= Examples
	
	http://www.germane-software/repositories/public/SVG/test/schedule.rb
	
	= Notes
	
	The default stylesheet handles upto 10 data sets, if you
	use more you must create your own stylesheet and add the
	additional settings for the extra data sets. You will know
	if you go over 10 data sets as they will have no style and
	be in black.
	
	Note that multiple data sets within the same chart can differ in 
	length, and that the data in the datasets needn't be in order; 
	they will be ordered by the plot along the X-axis.
	
	The dates must be parseable by ParseDate, but otherwise can be
	any order of magnitude (seconds within the hour, or years)
	
	= See also
	
	* SVG::Graph::Graph
	* SVG::Graph::BarHorizontal
	* SVG::Graph::Bar
	* SVG::Graph::Line
	* SVG::Graph::Pie
	* SVG::Graph::Plot
	* SVG::Graph::TimeSeries
	
	== Author
	
	Sean E. Russell <serATgermaneHYPHENsoftwareDOTcom>
	
	Copyright 2004 Sean E. Russell
	This software is available under the Ruby license[LICENSE.txt]
	
	"""
	
	"The format string to be used to format the X axis labels"
	x_label_format = '%Y-%m-%d %H:%M:%S'
	
	"""
	Use this to set the spacing between dates on the axis.  The value
	must be of the form
	"\d+ ?((year|month|week|day|hour|minute|second)s?)?"
	
	e.g.
	
		graph.timescale_divisions = '2 weeks'
		graph.timescale_divisions = '1 month'
		graph.timescale_divisions = '3600 seconds'  # easier would be '1 hour'
	"""
	timescale_divisions = None
	
	"The formatting used for the popups.  See x_label_format"
	popup_format = '%Y-%m-%d %H:%M:%S'

	_min_x_value = None
	scale_x_divisions = False
	scale_x_integers = False
	bar_gap = True

	stylesheet_names = Graph.stylesheet_names + ['bar.css']

	def add_data(self, data):
		"""
		Add data to the plot.
	
		  # A data set with 1 point: Lunch from 12:30 to 14:00
		  d1 = [ "Lunch", "12:30", "14:00" ] 
		  # A data set with 2 points: "Cats" runs from 5/11/03 to 7/15/04, and
		  #                           "Henry V" runs from 6/12/03 to 8/20/03
		  d2 = [ "Cats", "5/11/03", "7/15/04",
				 "Henry V", "6/12/03", "8/20/03" ]
									   
		  graph.add_data( 
			:data => d1,
			:title => 'Meetings'
		  )
		  graph.add_data(
			:data => d2,
			:title => 'Plays'
		  )
	
		Note that the data must be in time,value pairs, and that the date format
		may be any date that is parseable by ParseDate.
		Also note that, in this example, we're mixing scales; the data from d1
		will probably not be discernable if both data sets are plotted on the same
		graph, since d1 is too granular.
		"""
		# The ruby version does something different here, throwing out
		#  any previously added data.
		super(Schedule, self).add_data(data)

	# copied from Bar
	# TODO, refactor this into a common base class (or mix-in)
	def get_bar_gap(self, field_size):
		bar_gap = 10 # default gap
		if field_size < 10:
			# adjust for narrow fields
			bar_gap = field_size / 2
		# the following zero's out the gap if bar_gap is False
		bar_gap = int(self.bar_gap) * bar_gap
		return bar_gap

	def validate_data(self, conf):
		super(Schedule, self).validate_data(conf)
		msg = "Data supplied must be (title, from, to) tripples!"
		assert len(conf['data']) % 3 == 0, msg

	def process_data(self, conf):
		super(Schedule, self).process_data(conf)
		data = conf['data']
		triples = grouper(3, data)
		
		labels, begin_dates, end_dates = zip(*triples)
		
		begin_dates = map(self.parse_date, begin_dates)
		end_dates = map(self.parse_date, end_dates)

		# reconstruct the triples in a new order
		reordered_triples = zip(begin_dates, end_dates, labels)
		
		# because of the reordering, this will sort by begin_date
		#  then end_date, then label.
		reordered_triples.sort()
		
		conf['data'] = reordered_triples

	def parse_date(self, date_string):
		return parse(date_string)
	
	def set_min_x_value(self, value):
		if isinstance(value, basestring):
			value = self.parse_date(value)
		self._min_x_value = value

	def get_min_x_value(self):
		return self._min_x_value
		
	min_x_value = property(get_min_x_value, set_min_x_value)
	
	def format(self, x, y):
		return x.strftime(self.popup_format)
	
	def get_x_labels(self):
		format = lambda x: x.strftime(self.x_label_format)
		return map(format, self.get_x_values())
	
	def y_label_offset(self, height):
		return height / -2.0
	
	def get_y_labels(self):
		# ruby version uses the last data supplied
		last = -1
		data = self.data[last]['data']
		begin_dates, start_dates, labels = zip(*data)
		return labels
	
	def draw_data(self):
		bar_gap = self.get_bar_gap(self.get_field_height())
		
		subbar_height = self.get_field_height() - bar_gap
		
		y_mod = (subbar_height / 2) + (self.font_size / 2)
		x_min,x_max,div = self._x_range()
		x_range = x_max - x_min
		width = (float(self.graph_width) - self.font_size*2)
		# time_scale
		#scale /= x_range
		scale = TimeScale(width, x_range)
		
		# ruby version uses the last data supplied
		last = -1
		data = self.data[last]['data']
		
		for index, (x_start, x_end, label) in enumerate(data):
			count = index + 1 # index is 0-based, count is 1-based
			y = self.graph_height - (self.get_field_height()*count)
			bar_width = scale*(x_end-x_start)
			bar_start = scale*(x_start-x_min)
			
			etree.SubElement(self.graph, 'rect', {
				'x': str(bar_start),
				'y': str(y),
				'width': str(bar_width),
				'height': str(subbar_height),
				'class': 'fill%s' % (count+1),
			})

			
	def _x_range(self):
		# ruby version uses teh last data supplied
		last = -1
		data = self.data[last]['data']
		
		start_dates, end_dates, labels = zip(*data)
		all_dates = start_dates + end_dates
		max_value = max(all_dates)
		if not self.min_x_value is None:
			all_dates.append(self.min_x_value)
		min_value = min(all_dates)
		range = max_value - min_value
		right_pad = divide_timedelta_float(range, 20.0) or relativedelta(days=10)
		scale_range = (max_value + right_pad) - min_value
		
		#scale_division = self.scale_x_divisions or (scale_range / 10.0)
		# todo, remove timescale_x_divisions and use scale_x_divisions only
		# but as a time delta
		scale_division = divide_timedelta_float(scale_range, 10.0)
		
		# this doesn't make sense, because x is a timescale
		#if self.scale_x_integers:
		#	scale_division = min(round(scale_division), 1)
		
		return min_value, max_value, scale_division
	
	def get_x_values(self):
		x_min, x_max, scale_division = self._x_range()
		if self.timescale_divisions:
			pattern = re.compile('(\d+) ?(\w+)')
			m = pattern.match(self.timescale_divisions)
			if not m:
				raise ValueError, "Invalid timescale_divisions: %s" % self.timescale_divisions
			
			magnitude = int(m.group(1))
			units = m.group(2)
			
			parameter = self.lookup_relativedelta_parameter(units)
			
			delta = relativedelta(**{parameter:magnitude})
			
			scale_division = delta

		return date_range(x_min, x_max, scale_division)

	def lookup_relativedelta_parameter(self, unit_string):
		from util import reverse_mapping, flatten_mapping
		unit_string = unit_string.lower()
		mapping = dict(
			years = ('years', 'year', 'yrs', 'yr'),
			months = ('months', 'month', 'mo'),
			weeks = ('weeks', 'week', 'wks' ,'wk'),
			days = ('days', 'day'),
			hours = ('hours', 'hour', 'hr', 'hrs', 'h'),
			minutes = ('minutes', 'minute', 'min', 'mins', 'm'),
			seconds = ('seconds', 'second', 'sec', 'secs', 's'),
		)
		mapping = reverse_mapping(mapping)
		mapping = flatten_mapping(mapping)
		if not unit_string in mapping:
			raise ValueError, "%s doesn't match any supported time/date unit"
		return mapping[unit_string]