pyx/timeaxis.py

   1 import datetime
   2 import graph, helper
   3
   4 """some experimental code for creating a time axis
   5 - it needs python 2.3 to be used (it is based on the new datetime data type)
   6 - a timeaxis is always based on the datetime data type (there is no distinction between times and dates)
   7 """
   8
   9 class _timemap:
  10     "time axis mapping based "
  11
  12     __implements__ = graph._Imap
  13
  14     def setbasepoints(self, basepoints):
  15         (self.x1, self.y1), (self.x2, self.y2) = basepoints
  16         self.dx = self.x2-self.x1
  17         self.dy = self.y2-self.y1
  18         if self.dx < datetime.timedelta(0):
  19             raise RuntimeError("reverse time axis is not expected to work") # and should not happen
  20
  21     def convert(self, x):
  22         # XXX float division of timedelta instances
  23         def mstimedelta(td):
  24             "return the timedelta in microseconds"
  25             return td.microseconds + 1000000*(td.seconds + 3600*24*td.days)
  26         return self.y1 + self.dy * mstimedelta(x - self.x1) / float(mstimedelta(self.dx))
  27         # we could store float(mstimedelta(self.dx)) instead of self.dx, but
  28         # I prefer a different solution (not based on huge integers) for the
  29         # future
  30
  31     def invert(self, y):
  32         f = (y - self.y1) / float(self.dy)
  33         return self.x1 + datetime.timedelta(days=f*self.dx.days, seconds=f*self.dx.seconds, microseconds=f*self.dx.seconds)
  34
  35
  36 class timetick(datetime.datetime):
  37
  38     def __init__(self, year, month, day, ticklevel=0, labellevel=0, label=None, labelattrs=[], **kwargs):
  39         datetime.datetime.__init__(self, year, month, day, **kwargs)
  40         self.ticklevel = ticklevel
  41         self.labellevel = labellevel
  42         self.label = label
  43         self.labelattrs = helper.ensurelist(labelattrs)[:]
  44
  45     def merge(self, other):
  46         if self.ticklevel is None or (other.ticklevel is not None and other.ticklevel < self.ticklevel):
  47             self.ticklevel = other.ticklevel
  48         if self.labellevel is None or (other.labellevel is not None and other.labellevel < self.labellevel):
  49             self.labellevel = other.labellevel
  50
  51
  52 class timetexter:
  53
  54     def __init__(self, formats="%c"):
  55         self.formats = formats
  56
  57     def labels(self, ticks):
  58         for tick in ticks:
  59             if tick.labellevel is not None and tick.label is None:
  60                 tick.label = tick.strftime(self.formats)
  61
  62
  63 class timeaxis(graph._axis, _timemap):
  64
  65      def __init__(self, part=[], rater=graph.axisrater(), **args):
  66         graph._axis.__init__(self, divisor=None, **args)
  67         if self.fixmin and self.fixmax:
  68             self.relsize = self.max - self.min
  69             self.relsize = 0.000001*self.relsize.microseconds + self.relsize.seconds + 3600*24*self.relsize.days
  70         self.part = part
  71         self.rater = rater
  72
  73
  74 class symbol(graph.symbol):
  75     "the preliminary symbol class uses its "
  76
  77     def minmidmax(self, point, i, mini, maxi, di, dmini, dmaxi):
  78         min = max = mid = None
  79         mid = point[i]
  80         if di is not None: min = point[i] - point[di]
  81         elif dmini is not None: min = point[i] - point[dmini]
  82         elif mini is not None: min = point[mini]
  83         if di is not None: max = point[i] + point[di]
  84         elif dmaxi is not None: max = point[i] + point[dmaxi]
  85         elif maxi is not None: max = point[maxi]
  86         if mid is not None:
  87             if min is not None and min > mid: raise ValueError("minimum error in errorbar")
  88             if max is not None and max < mid: raise ValueError("maximum error in errorbar")
  89         else:
  90             if min is not None and max is not None and min > max: raise ValueError("minimum/maximum error in errorbar")
  91         return min, mid, max
  92