from random import uniform
import random
import math

print """\documentclass{article}
\usepackage[pdftex,active,tightpage]{preview}
\setlength\PreviewBorder{2mm}
\usepackage{tikz}
\usepackage{tkz-fct}
\usetikzlibrary{shapes.misc}
\usetikzlibrary{shapes, calc, shapes,snakes} 
\usepackage{amsmath,amssymb}

\\begin{document}
\\begin{preview}
\\begin{tikzpicture}[scale=0.1,dot/.style={    thick,
    draw=gray,
    cross out,
    inner sep=0pt,
    minimum width=4pt,
    minimum height=4pt}]
"""

def getPositionFromOffset(px, py, angle, radius):
    x = px + radius * math.cos(math.radians(angle))
    y = py + radius * math.sin(math.radians(angle))
    return (x, y)

n = 5
xSum = 0
ySum = 0
coordinates = [(0,0)]

random.seed(13)

for i in range(n-1):
	radius = uniform(0,20)
	angle = uniform(0, 360)
	px, py = coordinates[-1]
	x, y = getPositionFromOffset(px, py, angle, radius)
	xSum += x
	ySum += y
	coordinates.append((x,y))

center = (float(xSum) / n, float(ySum) / n)

cx, cy = center
coordinates.append((cx+15, cy))

pointCoords = ""
for p in coordinates:
	px, py = p	
	px -= cx
	py -= cy
	newP = "(%.2f,%.2f)," % (px, py)
	pointCoords = newP + pointCoords
	deltaY = 0-py
	deltaX = 0-px
	length = (deltaY**2+deltaX**2)**0.5
	sinAlpha = deltaY/length
	cosAlpha = deltaX/length
	print("\draw[->] (%.2f,%.2f) -- (%.2f,%.2f);" % (px, py, px+cosAlpha*length*0.80, py+sinAlpha*length*0.80))

print("\\node[circle,inner sep=1pt,fill]  at (%.2f,%.2f) {};" % (0, 0))

print("\\foreach \point in {" + pointCoords[:-1] + "}{")
print("\\node[dot] at \point {};")
print("}")

################################################################################
random.seed(17)
xSum = 0
ySum = 0
coordinates = [(0,0)]
for i in range(n-1):
	radius = uniform(0,20)
	angle = uniform(0, 360)
	px, py = coordinates[-1]
	x, y = getPositionFromOffset(px, py, angle, radius)
	xSum += x
	ySum += y
	coordinates.append((x,y))

center = (float(xSum) / n, float(ySum) / n)

cx, cy = center
coordinates.append((cx-15,cy))
xOffset = 40
cTmp = []
for p in coordinates:
	px, py = p
	cTmp.append((px-cx+xOffset,py-cy))	

coordinates = cTmp
cx, cy = xOffset, 0
pointCoords = ""

for p in coordinates:
	px, py = p	
	newP = "(%.2f,%.2f)," % (px, py)
	pointCoords = newP + pointCoords
	deltaY = -py
	deltaX = xOffset-px
	length = (deltaY**2+deltaX**2)**0.5
	sinAlpha = deltaY/length
	cosAlpha = deltaX/length
	print("\draw[->] (%.2f,%.2f) -- (%.2f,%.2f);" % (px, py, px+cosAlpha*length*0.80, py+sinAlpha*length*0.80))


print("\\node[circle,inner sep=1pt,fill]  at (%.2f,%.2f) {};" % (xOffset, 0))

print("\\foreach \point in {" + pointCoords[:-1] + "}{")
print("\\node[dot] at \point {};")
print("}")

##################################

print("\\node[circle,inner sep=1pt,fill]  at (%.2f,%.2f) {};" % (xOffset, 0))

print("\\foreach \point in {(15,0), (35,0)}{")
print("\\node[dot] at \point {};")
print("}")


print """
\end{tikzpicture}
\end{preview}
\end{document}
"""
