/
dtree_draw.py
47 lines (34 loc) · 1.42 KB
/
dtree_draw.py
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from PIL import Image, ImageDraw
from dtree_build import decisionnode
def getwidth(tree):
if tree.tb == None and tree.fb == None: return 1
return getwidth(tree.tb) + getwidth(tree.fb)
def getdepth(tree):
if tree.tb == None and tree.fb == None: return 0
return max(getdepth(tree.tb), getdepth(tree.fb)) + 1
def drawtree(tree, jpeg='tree.jpg'):
w = getwidth(tree) * 100
h = getdepth(tree) * 100 + 120
img = Image.new('RGB', (w, h), (255, 255, 255))
draw = ImageDraw.Draw(img)
drawnode(draw, tree, w / 2, 20)
img.save(jpeg, 'JPEG')
def drawnode(draw, tree, x, y):
if tree.results == None:
# Get the width of each branch
w1 = getwidth(tree.fb) * 100
w2 = getwidth(tree.tb) * 100
# Determine the total space required by this node
left = x - (w1 + w2) / 2
right = x + (w1 + w2) / 2
# Draw the condition string
draw.text((x - 20, y - 10), str(tree.col)[0:5] + ':' + str(tree.value), (0, 0, 0))
# Draw links to the branches
draw.line((x, y, left + w1 / 2, y + 100), fill=(255, 0, 0))
draw.line((x, y, right - w2 / 2, y + 100), fill=(255, 0, 0))
# Draw the branch nodes
drawnode(draw, tree.fb, left + w1 / 2, y + 100)
drawnode(draw, tree.tb, right - w2 / 2, y + 100)
else:
txt = ' \n'.join(['%s:%d' % v for v in tree.results.items()])
draw.text((x - 20, y), txt, (0, 0, 0))