#!/usr/bin/env python

import math
import matplotlib
from matplotlib.transforms import Affine, multiply_affines, \
     translation_transform, Value, zero
from matplotlib.patches import Rectangle
import pylab

# First build a figure
fig = pylab.figure()
ax = fig.add_subplot(111)
ax.plot([0,1,2,3,4,5,6,7,8,9],'o')
ax.set_aspect('equal')

# Where we want the rectangle
x,y,w,h = 2,5,2,2
# How much to rotate
angle = math.pi/3
# We will rotate around the center
cx,cy = x+w/2.0,y+h/2.0

# Rotation:
cos = Value(math.cos(angle))
sin = Value(math.sin(angle))
rotate = Affine(cos, zero()-sin, sin, cos, zero(), zero())

# Rotate around center:
to_origin = translation_transform(Value(-cx),Value(-cy))
and_back = translation_transform(Value(cx),Value(cy))
trans = multiply_affines(multiply_affines(and_back,rotate),to_origin)

# The transformation must be combined with ax.transData,
#   but that is not an Affine...
origin, unit = map(ax.transData.xy_tup, [(0,0),(1,1)])
scalex, scaley = unit[0]-origin[0], unit[1]-origin[1]
transData = Affine(Value(scalex), zero(), zero(), Value(scaley),
                   Value(origin[0]), Value(origin[1]))
final_trans = multiply_affines(transData,trans)

rec = Rectangle((x,y),w,h,ec=[1,0,0],fc=[0,1,.7],lw=2,
                transform=final_trans)
ax.add_patch(rec)

pylab.show()