Lib/lib-stdwin/Histogram.py

   1 # Module 'Histogram'
   2
   3 from Buttons import *
   4
   5 # A Histogram displays a histogram of numeric data.
   6 #
   7 class HistogramAppearance(LabelAppearance, Define):
   8         #
   9         def define(self, parent):
  10                 Define.define(self, (parent, ''))
  11                 self.ydata = []
  12                 self.scale = (0, 100)
  13                 return self
  14         #
  15         def setdata(self, ydata, scale):
  16                 self.ydata = ydata
  17                 self.scale = scale # (min, max)
  18                 self.parent.change(self.bounds)
  19         #
  20         def drawpict(self, d):
  21                 (left, top), (right, bottom) = self.bounds
  22                 min, max = self.scale
  23                 size = max-min
  24                 width, height = right-left, bottom-top
  25                 ydata = self.ydata
  26                 npoints = len(ydata)
  27                 v1 = top + height       # constant
  28                 h1 = left               # changed in loop
  29                 for i in range(npoints):
  30                         h0 = h1
  31                         v0 = top + height - (ydata[i]-min)*height/size
  32                         h1 = left + (i+1) * width/npoints
  33                         d.paint((h0, v0), (h1, v1))
  34         #
  35
  36 class Histogram(NoReactivity, HistogramAppearance): pass