Programming for Social Scientists Lecture 6 UCLA Political Science 209-1: Programming for Social...

Programming for Social Scientists

Lecture 6UCLA Political Science 209-1: Programming for Social

Scientists

Winter 1999

Lars-Erik Cederman & Benedikt Stefansson

POL SCI 209-1 Cederman / Stefansson

2

Today's topics

Graphical User Interfaces (GUIs)– graphs– control panels

Example 1: GraphIPDProgram that endows EvolIPD with a dynamic

graph and a control panel.

Example 2: Elevator


3

The Graphical User Interface

• Objects provided to create and manage – Line graphs

– Histograms

– Raster images

– Digraphs

• Data collection, calculation and updating is provided through support objects to the GUI widgets


4

GraphIPD: Adding GUImain

EZGraph

ModelSwarmpopList

Tournament

newListwinner

ControlPanel

ObserverSwarm


5

Creating a graph

• EZGraph class sets up line graph for either– Single agent or object

– Collection of agents

• In both cases need– Name of sequence

– Type of sequence {Count, Total, Average, Min, Max}

– Target (object or collection)

– Name of method to get data

Agent

AveragerCollection


6

Graph IPD: File Structure

main.mModel-Swarm.m

Tourna-ment.m

Tourna-ment.h

Model-Swarm.h

Observer-Swarm.m

Observer-Swarm.h

Player.m

Player.h


7

GraphIPD: main.m

#import <simtools.h>

#import "ObserverSwarm.h"

int main(int argc,const char ** argv) {

ObserverSwarm * observerSwarm;

initSwarm(argc, argv);

observerSwarm = [ObserverSwarm create: globalZone];

[observerSwarm buildObjects];

[observerSwarm buildActions];

[observerSwarm activateIn: nil];

[observerSwarm go];

return 0;

}


8

GraphIPD: ObserverSwarm.h

@interface ObserverSwarm : GUISwarm {

int displayFrequency;

id displayActions;

id displaySchedule;

id modelSwarm;

id <EZGraph> numGraph;

}

+createBegin: (id) aZone;

-createEnd;

-buildObjects;

-buildActions;

-activateIn: (id) swarmContext;

@end


9

Creating an ObserverSwarm

• createBegin,createEnd – Initialize memory and parameters

• buildObjects– Build ModelSwarem

– Build graphs, rasters and probes

• buildActions– Define order and timing of GUI events

• activate


10

Step I: Initializing

+ createBegin: aZone {

ObserverSwarm *obj;

obj = [super createBegin: aZone];

obj->displayFrequency = 1;

return obj;

}


11

Step II: Creating objects

-buildObjects {

[super buildObjects];

modelSwarm = [ModelSwarm createBegin: self];

modelSwarm = [modelSwarm createEnd];

[modelSwarm buildObjects];

// cont'd


12

Step II: Creating objects (cont'd)

numGraph = [EZGraph createBegin: self];

[numGraph setTitle: "Number of all-C"];

[numGraph setAxisLabelsX: "Time" Y: "Number"];

numGraph = [numGraph createEnd];

[numGraph createSequence: "all-C" withFeedFrom: modelSwarm andSelector: M(getNum0)];

[numGraph createSequence: "TFT" withFeedFrom: modelSwarm andSelector: M(getNum1)];

[numGraph createSequence: "aTFT" withFeedFrom: modelSwarm andSelector: M(getNum2)];

[numGraph createSequence: "all-D" withFeedFrom: modelSwarm andSelector: M(getNum3)];

[controlPanel setStateStopped];

return self;

}


13

-buildActions {

[super buildActions];

displayActions = [ActionGroup create: self];

[displayActions createActionTo: modelSwarm message: M(step)];

[displayActions createActionTo: numGraph message: M(step)];

[displayActions createActionTo: actionCache message: M(doTkEvents)];

displaySchedule = [Schedule createBegin: self];

[displaySchedule setRepeatInterval: 1];

displaySchedule = [displaySchedule createEnd];

[displaySchedule at: 0 createAction: displayActions];

return self;

}

Step III: Building actions


14

Step IV: Activating

-activateIn: (id) swarmContext {

[super activateIn: swarmContext];

// If modelSwarm also has activity schedule:

// [modelSwarm activateIn: self];

[displaySchedule activateIn: self];

return [self getSwarmActivity];

}


15

Major Analysis classes

• EZGraph– Combines several objects to

gather and display data on line graph

• EZBin– Does same for histogram

• Averager, Entropy and EZDistribution– Collect statistics from

collection of objects

Averager

EZGraph

EZBin

Objectbase

Entropy

EZDistribution

Probe


16

Using EZGraph

• EZGraph is a wrapper around several objects

• Allows creation and setup to be achieved in one fell swoop

• After setting title and labels must add one or more sequences

• Necessary steps:1) create an instance

2) setTitle: titleString

3) setAxisLabelsX: str Y: str

4) Add sequence(s) – With feed from object

– Or feed from collection: AverageSequence

TotalSequence

MinSequence MaxSequence


17

Creating an EZGraph

A sequence with feed from collection is created with-createASequence: aString withFeedFrom: collection andSelector: M(method)where A is one of Average, Total, Min, Max or Count

aString

The title, made with:-setTitle: aString

The axis labels, set with-setAxisLabelsX: str Y: str


18

Using EZBin

• EZBin, is also a wrapper around several objects

• This type of graph needs to be told the number of bins for histogram and interval in which values lie

• Necessary steps:1) create an instance

2) setTitle: titleString

3) setCollection: collection

4) setProbedSelector:M(method)

5) setBinNum: n

6) setUpperBound: and setLowerBound:


19

Creating an EZBin

Data is fed into Histogram by-setCollection: collectionand-setProbedSelector:M(method)

The title, made with:-setTitle: aString

The axis labels, set with-setAxisLabelsX: str Y: str

The number of bins is determined with-setNumBins: numand the range of values by-setUpperBound: -setLowerBound:


20

Other utility objects in Analysis

• Averager– Gets feed from

collection and calculates:

• Average

• Total

• Min

• Max

• Count

• Entropy– Gets feed from

collection and calculates entropy assuming data is probabilities

• EZDistribution– Subclass of EZBin,

gives acces to underlying distribution of data


21

Homework Week 6

1. Modify GraphIPD sample program:a. Add a second graph plotting the average payoff

of the players over time

b. Replace frequency graph with histogram showing the frequency of the four strategies dynamically

2. Extend Elevator sample program to n-tenant case


22

Homework Week 6: Exercise 2

0

1

2

3

Apartment

building with

elevator:

What is the

average waiting

time?

...

nTwo types of elevators:•Type 0: "standard" Car remains where it is after use•Type 1: "modified" Car returns to zero after use


23

Assignment:a. Derive theoretical waiting times for n=2.

b. Generalize the program Elevator from two-tenant case to any n.

c. Simulate the estimated waiting time for both elevator types.

d. Plot the waiting times as a function of n.

e. Which elevator type minimizes waiting?

*f. Derive theoretical waiting times for n.


24

Theoretical average waiting times for elevator types 0 and 1

EW(n,0) 1

3n(n2 1)

EW(n,1) n 1

4

n = number of stories


25

Elevator: main.mint main(int argc, const char ** argv) {

...

for (eType = 0; eType < 2; eType++) {

[tenant1 init: 1];

[tenant2 init: 2];

[elevator init: 2 type: eType];

for (repl = 0; repl < n; repl++) {

if ([uniformIntRand getIntegerWithMin: 0 withMax: 1])

[tenant1 move: elevator];

else

[tenant2 move: elevator];

}

printf("Type: %d Time: %10.6f \n",

eType,

(double) ([tenant1 getTime]+[tenant2 getTime])/(double) n);

}

return 0;

}


26

Elevator: Tenant.h...

@interface Tenant: SwarmObject {

int floor, homeFloor;

int waitingTime, trips;

}

-init: (int) n;

-setFloor: (int) f;

-(BOOL)isAtHome;

-(int)getTime;

-move: (id) e;

@end


27

Elevator: Tenant.m...-init: (int) n { homeFloor = n; if ([uniformIntRand getIntegerWithMin: 0 withMax: 1]) floor = homeFloor; else floor = 0; waitingTime = 0; trips = 0; return self;}...-move: (id) e { waitingTime = waitingTime + [e callAtFloor: floor]; if ([self isAtHome]) [e take: self toFloor: 0]; else [e take: self toFloor: homeFloor]; trips++; return self;}


28

Elevator: Elevator.h...

@interface Elevator: SwarmObject {

int floor;

int type;

}

-init: (int) nFloors type: (int) eType;

-(int)getFloor;

-(int)callAtFloor: (int) f; // returns waiting time!

-take: (id) t toFloor: (int) f;

@end


29

Elevator: Elevator.m (1)...

@implementation Elevator

-init: (int) nFloors type: (int) eType {

type = eType;

if (type)

floor = 0;

else {

if ([uniformIntRand getIntegerWithMin: 0 withMax: 1])

floor = 0;

else

floor = [uniformIntRand getIntegerWithMin: 1 withMax: nFloors];

}

return self;

}

...


30

Elevator: Elevator.m (2)...

-(int)callAtFloor: (int) f {

int wait;

wait = abs(floor-f);

floor = f;

return wait;

}

-take: (id) t toFloor: (int) f {

[t setFloor: f];

if (type==1)

floor = 0;

else

floor = f;

return self;

}

@end

Programming for Social Scientists Lecture 6 UCLA Political Science 209-1: Programming for Social...

Documents

Transcript of Programming for Social Scientists Lecture 6 UCLA Political Science 209-1: Programming for Social...