CS 5 “Black” • Assignment 10 on the web!

– Lab and reading due at normal times (this Sunday at 11:59 PM)

– All the rest is due the following Thursday (Nov. 20) at 11:59 PM

– Some choices!

• Markov text generation

• 3D video game

• Lempel-Ziv (+20 points!)

• Connect 4 AI (+20 points!)

• Exam 2

– Monday, November 17

– Covers everything through this Wednesday’s lectures

– Emphasis on material since last exam, but recursion is fair game!

– One 8.5 x 11 sheet (front and back) permitted

– If you are asked to program in Hmmm, we’ll provide you the full instruction set

– Practice problems now on the CS 5 website

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return vs print

def foo1():print 42

def foo2()return 42

def bar()x = foo1()y = foo2()

x += 1 y += 42

This is good foo for thought!

que es eso?

True Story

kth Order Markov Processes

Andrey Markov 1856-1922

Training File: “I like spam. I liketoast and spam. I eat benand jerry’s ice cream too.”

First order Markov Dictionary: I : like, like, eat like : spam, toast spam. : I, I and : spam, jerry’s

kth Order Markov Processes

Andrey Markov 1856-1922

Training File: “I like spam. I liketoast and spam. I eat benand jerry’s ice cream too.”

First order Markov Dictionary: I : like, like, eat like : spam, toast spam. : I, I and : spam, jerry’s MORE ENTRIES…

Generating “random” text: “I like spam. I like spam.” “I eat ben and spam. I like toast

and jerry's ice cream too."

kth Order Markov Processes

Andrey Markov 1856-1922

Training File: “I like spam. I liketoast and spam. I eat benand jerry’s ice cream too.”

First order Markov Dictionary: I : like, like, eat like : spam, toast spam. : I, I and : spam, jerry’s MORE ENTRIES…Second order Markov Dictionary: I like : spam., toast like spam. : I spam. I : like, eat

kth Order Markov Processes

Andrey Markov 1856-1922

Training File: Wikipedia essay on Huffman Compression

First order Markov sentencesgenerated…

“Huffman was a source symbol.”

“Huffman became a known as a character in a particular symbol frequencies agree with those used for each possible value of Engineering.”

kth Order Markov Processes

Training File: Wikipedia essay on Huffman Compression

Second order Markov sentencesgenerated…

“Huffman coding is such a code is not produced by Huffman's algorithm.”

“Huffman was able to design the most common characters using shorter strings of bits than are used for lossless data compression.”

Thinking Rationally

class Rational:def _ _init_ _(self, num, denom): self.numerator = num if denom == 0: print “Invalid Denominator!” else:

self.denominator = denom

def isZero(self): return self.numerator == 0

>>> myNum1 = Rational(1, 3)>>> myNum2 = Rational(0, 6)

Why is this code so selfish?

numerator = 1denominator = 3

numerator = 0denominator = 6

myNum1

myNum2

The “constructor”

Rational is a classand MyNum1 and MyNum2 are “objects”or “instances” of the Rational class

Thinking Rationally

class Rational:def _ _init_ _(self, num, denom): self.numerator = num if denom == 0: print “Invalid Denominator!” else:

self.denominator = denom

def isZero(self): return self.numerator == 0

>>> myNum1 = Rational(1, 3)>>> myNum2 = Rational(0, 6)>>> myNum1.isZero()False>>> myNum2.isZero()

Why is this code so selfish?

numerator = 1denominator = 3

numerator = 0denominator = 6

myNum1

myNum2

The “constructor”

Thinking Rationally

class Rational:def _ _init_ _(self, num, denom): self.numerator = num self.denominator = denom

def _ _repr_ _ (self): return str(self.numerator) + “/” + str(self.denominator)

>>> myNum1 = Rational(1, 3)>>> myNum11/3>>> print “This is my number:”+str(myNum1)

equivalent to myNum1._ _repr()_ _

Thinking Rationally

class Rational:def _ _init_ _(self, num, denom): self.numerator = num self.denominator = denom

def equals(self, OtherNum): return self.numerator * OtherNum.denominator ==

self.denominator * OtherNum.numerator

>>> myNum1 = Rational(1, 3)>>> myNum2 = Rational(2, 6)>>> myNum1.equals(myNum2)True

1

3

2

6

Cross multiplication!

Thinking Rationally

class Rational:def _ _init_ _(self, num, denom): self.numerator = num self.denominator = denom

def _ _eq_ _(self, OtherNum): return self.numerator * OtherNum.denominator ==

self.denominator * OtherNum.numerator

>>> myNum1 = Rational(1, 3)>>> myNum2 = Rational(2, 6)>>> myNum1 == myNum2True

myNum1._ _eq_ _(myNum2)

Overloaded Operator Naming

+ __add__

- __sub__

* __mul__

/ __div__

// __floordiv__

% __mod__

** __pow__

+ __pos__

- __neg__

__abs__

__int__

__float__

__complex__

== __eq__

!= __ne__

<= __le__

>= __ge__

< __lt__

> __gt__

>>> myNum = Rational(9, 2)

>>> myNum.int()

Barf!

>>> int(myNum)

4

def __int__(self): return self.numerator/self.denominator

Very __int__eresting!

Rationals Revisitedclass Rational:

def _ _init_ _(self, num, denom): self.numerator = num self.denominator = denom

def _ _repr_ _ (self): return str(self.numerator) + “/” + str(self.denominator)

def _ _eq_ _(self, other): return self.numerator * other.denominator == self.denominator * other.numerator

def _ _add_ _(self, other): ```Returns a new Rational number that is the sum of self and

other’’’

Worksheet

>>> myNum1 = Rational(1, 3)>>> myNum2 = Rational(3, 5)>>> myNum3 = myNum1 + myNum2>>> myNum314/15

Rationals Revisitedclass Rational:

def _ _init_ _(self, num, denom): self.numerator = num self.denominator = denom

def _ _add_ _(self, other):newDenominator = self.denominator * other.denominatornewNumerator = self.numerator*other.denominator +

other.numerator*self.denominator return Rational(newNumerator, newDenominator)

>>> myNum1 = Rational(1, 3)>>> myNum2 = Rational(3, 5)>>> myNum3 = myNum1 + myNum2>>> myNum314/15

A Vector Class

>>> tuple1 = (1, 0, 2)>>> tuple2 = (1, 0, 2)>>> tuple1 + tuple2(1, 0, 2, 1, 0, 2)>>> u = Vector(tuple1)>>> v = Vector(tuple2)>>> u(1, 0, 2)>>> u == vTrue>>> u+v(2, 0, 4)>>> u*v5

Worksheet

Dot product!

A Vector Classclass Vector: def __init__(self, inputTuple):

self.x = inputTuple[0]self.y = inputTuple[1]self.z = inputTuple[2]

def __eq__(self, other): return self.x == other.x and self.y == other.y and self.z == other.z

def __add__(self, other): return Vector((self.x + other.x, self.y + other.y, self.z + other.z))

def __repr__(self): return "("+str(self.x)+","+str(self.y)+","+str(self.z)+")"

def __mul__(self, other): return (self.x * other.x) + (self.y * other.y) + (self.z * other.z)

A Self-Counting Classclass Person: population = 0 def __init__(self, InputName, ID): self.name = InputName self.ID = ID population = population+1

>>> Person.population 0>>> P1 = Person(“Matt”, 42)>>> P2 = Person(“Sarah”, 27)>>> P1.ID 42>>> Person.population2

Named Arguments

def foo(ID, Name=“Student”, Food=“Spam”):

foo(42)foo(43, “Nick”)foo(44, “Matt”, “Pop Tarts”)foo(Food = “Pizza”, ID = 45)foo(Name = “Meera”, Food = “M&Ms”, ID=46)foo(Food = “Spam”, Name =“Kylie”)

This is cool!

3D Graphics with vPython!

>>> from visual import *>>> mybox1 = box(pos=(0,0,0),length=1,height=1, width=1,color=(1,0,0))

>>> mybox2 = box(pos=(3, 0, 0),length=1,height=1,

width=1,color=(0,1,0))

Draws the box (cube)and returns a reference tothat box!

What does that reference look like and what can we do with it?

Notice the named arguments!

3D Graphics with vPython!

>>> from visual import *>>> mybox1 = box(pos=(0,0,0),length=1,height=1, width=1,color=(1,0,0))

THIS IS A NAMED ARGUMENT - SETTING A VECTOR that is the centerof the box!

What does that reference look like and what can we do with it?

Demo!

Rotating Cubefrom visual import * # imports the graphics module!

def spinbox(): myBox = box(pos=(0,0,0),length=1,height=1,width=1,color=(1,0,0)) while True: scene.autoscale = False # Turn off weird autozoom rate(30) # Limit the animation rate to 30 fps myBox.rotate(angle=pi/100,axis=(1,0,0),origin=(0,0,0))

Demo!spinbox.py

from visual import *import random

def spinboxes():boxList = []for boxNumber in range(0, 10):

x = random.randint(-5, 5)y = random.randint(-5, 5)z = random.randint(-5, 5)red = random.random() # random number between 0 and 1green = random.random() # random number between 0 and 1blue = random.random() # random number between 0 and 1newBox = box(pos=(x, y, z), length=1, height=1, width=1, color=(red, green, blue))boxList.append(newBox)

while True:for myBox in boxList: scene.autoscale = False # Turn off weird autozoom myBox.rotate(angle=pi/100, axis=(1, 0, 0), origin=(0, 0, 0))

Lots of Rotating Cubes!

Demo!spinboxes.py

What is this program doing?

Iteration + Recursion = ;^)

fractalCube(level, size, x, y, z)

fractalCube(0, 9, 0, 0, 0)

fractalCube(1, 9, 0, 0, 0)

fractalCube(2, 9, 0, 0, 0)

size = 9

93

3Notice how the centers are offset!

Iteration + Recursion = ;^)

def fractalCube(level, size, x, y, z): ```Returns a list of boxes comprising

the fractal cube of given sizecentered at x, y, z’’’

if level == 0:return ???

else: No more than 7 lines of code here!

box(pos=(0,0,0), length=1, height=1, width=1,color=(1, 0, 0) )

Iteration + Recursion = ;^)

def fractalCube(level, size, x, y, z): ```Returns a list of boxes comprising

the fractal cube of given sizecentered at x, y, z’’’

if level == 0:return [box(pos=(x,y,z),

length=size, height=size, …)]else:

newsize = size/3.0cubeList = []for newx in [x-newsize, x+newsize]: for newy in [y-newsize, y+newsize]: for newz in [z-newsize, z+newsize]:

cubeList = cubeList + fractalCube(level-1,newsize, newx, newy, newz)

return cubeList

Demo!fractalcube.py

Rotate those cubes!

myCubes = fractalcubes(3, 50, 0, 0, 0)while True: for cube in myCubes: scene.autoscale = False # No weird autozoom cube.rotate(angle=pi/100, axis=(1,0,0),

origin=(0,0,0))

myCubes = fractalcubes(3, 50, 0, 0, 0)while True: for cube in myCubes: scene.autoscale = False # No weird autozoom cube.rotate(angle=pi/100, axis=(1,0,0),

origin=cube.pos))

Demo!rotate.py

Jiggling cubes!

import random

myCubes = fractalcubes(3, 50, 0, 0, 0)while True: for cube in myCubes: scene.autoscale = False # No weird autozoom cube.pos = cube.pos +

(random.random(),random.random(),random.random())

Returns a random number between 0 and 1

Will this jiggle?

Jiggling cubes!

import random

myCubes = fractalcubes(3, 50, 0, 0, 0)while True: for cube in myCubes: scene.autoscale = False # No weird autozoom cube.pos = cube.pos +

(random.random()-0.5, random.random()-0.5, random.random()-0.5)

I gotta see this!

Demo!jiggles.py

Classes with Class!

>>> myBlob = blob(0, 0, 0)>>> myBlob.move(0.1, 0, 0)

class blob: def __init__(self, x, y, z): self.sphere1 = ellipsoid(pos=(x-0.25,y,z)) self.sphere2 = ellipsoid(pos=(x+0.25,y,z)) self.sphere3 = ellipsoid(pos=(x,y+0.25,z)) self.spheres=[self.sphere1, self.sphere2, self.sphere3] def move(shiftx, shifty, shiftz): worksheet

Classes with Class!

>>> myBlob = blob(0, 0, 0)>>> myBlob.move(0.1, 0, 0)

class blob: def __init__(self, x, y, z): self.sphere1 = ellipsoid(pos=(x-0.25,y,z)) self.sphere2 = ellipsoid(pos=(x+0.25,y,z)) self.sphere3 = ellipsoid(pos=(x,y+0.25,z)) self.spheres=[self.sphere1, self.sphere2, self.sphere3] def move(shiftx, shifty, shiftz): for sphere in self.spheres: sphere.pos += (shiftx, shifty, shiftz)

Balls and Wallsfrom visual import *

def main(): redball = sphere(pos = (0, 0, 0), radius = 1, color=color.red) rightwall = box(pos = (5, 0, 0), length = 1, height = 10, width = …) leftwall = box(pos = (-5, 0, 0), length = 1, height = 10, width = …) travel = vector(0.05, 0, 0) # vector, victor! wallshift = vector(0, 0, 0.2) # roger, roger! while True: scene.autoscale = False rate(60) if scene.kb.keys: # key pressed? key = scene.kb.getkey() # get the key that was pressed! if key == "f": travel = -1*travel if key == "d": rightwall.pos = rightwall.pos + wallshift if key == "s": rightwall.pos = rightwall.pos - wallshift if (redball.pos.x > 3.75 or redball.pos.x < -3.75): travel = -1*travel # NEGATING A VECTOR! redball.pos = redball.pos+travel

Demo!bounce.py

More on vPython

www.vpython.org

Also keyboard and mouse control functions and much, much more!

On the homework…

• Lab 1• Reading• Connect4 Board• One of…

– Markov text generation– Your own video game– Lempel-Ziv (+20 points!)– Connect 4 Player with AI (+20 points!)

You should understand the ideas behind doing each of these, even if you don’t actually program them.

Worksheet Challenge!

• Define Foo and Bar such that python has the following behavior…

>>> Foo[0] == BarTrue>>> Bar[0] == FooTrue

>>> Foo[0][0][0][0][0] == FooTrue

That’s TOO weird!!