Graphically Displaying Data PDF

Preview

Summary

Download Graphically Displaying Data PDF

Description

1

I.SourcesforDataandArticles  ResourcesforEconomistsontheInternet (http://rfe.org)  EconLit (fromtheUniversityLibrarywebpage, chooseArticles/ElectronicDatabasesA‐Z)  NationalBureauofEconomicResearchWorking Papers(availableforfreethroughLibrary,under “ElectronicJournals”)  ResearchPapersinEconomics(RePEc), (http://repec.org/)  FRED(https://fred.stlouisfed.org/) (c)MarkV.Siegler(Donotciteorcirculate)

2

1

II.PropertiesofGoodGraphs        

InformationallyRich,ButNotCluttered ClearandSelf‐Contained AestheticallyPleasing FitsinwiththeSurroundingText AvoidsGridlines,Legends,PoorColorSchemes,etc. LooksGoodinBothColorandBlackandWhite Avoids3‐D UsesRatioScaling(WheneverPossible)and ReasonableScalingandUnitsofMeasurementon theAxes (c)MarkV.Siegler(Donotciteorcirculate)

3

SomeBadGraphs...

(c)MarkV.Siegler(Donotciteorcirculate)

4

2

(c)MarkV.Siegler(Donotciteorcirculate)

5

AnotherBadGraph The CaliforniaAggie,May24,2011

(c)MarkV.Siegler(Donotciteorcirculate)

6

3

Morefrom The CaliforniaAggie,May26,2012

(c)MarkV.Siegler(Donotciteorcirculate)

7

BadPieChart (SharesShouldAlwaysSumto100Percent)

(c)MarkV.Siegler(Donotciteorcirculate)

8

4

TerriblePieCharts

(c)MarkV.Siegler(Donotciteorcirculate)

9

TerriblePieCharts

(c)MarkV.Siegler(Donotciteorcirculate)

10

5

SomeBetterExamples...

(c)MarkV.Siegler(Donotciteorcirculate)

11

Americans' Views on Immigration

Present Level 39%

Don't Know/No Opinion 4%

Increased 28%

Decreased 29% Should immigration be kept at its present level, increased, or decreased? Gallup Poll, June 21, 2018.

(c)MarkV.Siegler(Donotciteorcirculate)

12

6

20 10 0

Percent

30

40

Americans' View of Immigration

Remain the Same Increased Decreased Don't Know/No Opinion Should immigation be increased, decreased, or remain the same? (c)MarkV.Siegler(Donotciteorcirculate)

13

(c)MarkV.Siegler(Donotciteorcirculate)

14

7

(c)MarkV.Siegler(Donotciteorcirculate)

15

16

8

Figure7.7 TotalFertilityRatesintheUnitedStates 1800to2010 9 Black

NumberofChildrenperWoman

8 7

White

6 5 4 Hispanic

3 2

Asian

1 0 1800

1820

1840

1860

1880

1900

1920

1940

1960

1980

2000

(c)MarkV.Siegler(Donotciteorcirculate)

17

(c)MarkV.Siegler(Donotciteorcirculate)

18

9

WorldPopulation,1750to2000 LinearScaling 7000

6000

MillionsofPeople

5000

4000

3000

2000 1000

0 1750

1800

1850

1900

1950

2000

(c)MarkV.Siegler(Donotciteorcirculate)

19

WorldPopulation,1750to2000 RatioScaling 10000

MillionsofPeople

1000

100

10

1 1750

1800

1850

1900

(c)MarkV.Siegler(Donotciteorcirculate)

1950

2000

20

10

DifferentScalingCanLeadto (Radically)DifferentInterpretations

(c)MarkV.Siegler(Donotciteorcirculate)

21

(c)MarkV.Siegler(Donotciteorcirculate)

22

11

(c)MarkV.Siegler(Donotciteorcirculate)

23

III.TypesofGraphsinR PieCharts:pie() BarandColumnCharts:barplot() BoxandWhiskerPlots:boxplot() Histograms:hist() (Time‐Series)LineGraphs:plot().Toputthe datesonthehorizontalaxis,useats object  ScatterDiagram:plot(x,y)     

See Quick-R graphs at: https://www.statmethods.net/graphs/index.html (c)MarkV.Siegler(Donotciteorcirculate)

24

12

IV.ParametersforGraphsinR  main, xlab, ylab (Graphtitle,x‐axislabel,y‐

axislabel)  lwd, lty (linewidthandlinetype,lwd = 3,for exampleleadstoathickerlinethatlwd = 2)  xlim, ylim (providesthelimitsforthehorizontal axisrangeandtheverticalaxisrange,respectively)  col (colororcolorstobeusedingraph).Forallthe colorsRsupports,see http://www.stat.columbia.edu/~tzheng/files/Rcolor.pdf

 font.lab (fontsforthelabels)  font (fontselsewhereingraph) (c)MarkV.Siegler(Donotciteorcirculate)

25

IV.ParametersforGraphsinR  breaks()providesintervalsforthevariablewhen

constructingafrequencydistribution(histogram). Withbreaks=c(2, 4, 6, 8),itwouldinclude thefrequencyofobservationsbelowandincluding2 inthefirstinterval,thoseabove2andincluding4in thesecondinterval,andsoon.

(c)MarkV.Siegler(Donotciteorcirculate)

26

13

V.AddingPoints,Lines,andTexttoGraphs  points (addspoints)  lines, abline, segments (addslinesto

graph)  text (writestext)  arrows (addsarrows)  legend (addslegend). Avoidusinglegends wheneverpossible.

(c)MarkV.Siegler(Donotciteorcirculate)

27

VI.ExampleofanRScriptforaPieChart x = c(1, 1, 1, 2, 2, 3, 4, 4, 4, 4) pie(table(x), main = "Distribution of Course Grades", labels=c("D grade (30%)", "C grade (20%)", "B grade (10%)", "A grade (40%)"), col = c("dark blue", "blue", "light blue", "white"))

(c)MarkV.Siegler(Donotciteorcirculate)

28

14

Distribution of Course Grades

D grade (30%) C grade (20%)

B grade (10%)

A grade (40%)

(c)MarkV.Siegler(Donotciteorcirculate)

29

VII.ExampleofanRScriptforaHistogram absent = c(1, 1, 2, 4) hist(absent, breaks = c(0.5, 1.5, 2.5, 3.5, 4.5), col="blue", main = "Frequency Distribution of Days Absent", freq=FALSE, ylim = c(0, 0.50), xlab = "Number of Days Absent")

(c)MarkV.Siegler(Donotciteorcirculate)

30

15

0.3 0.2 0.0

0.1

Density

0.4

0.5

Frequency Distribution of Days Absent

1

2

3

4

Number of Days Absent (c)MarkV.Siegler(Donotciteorcirculate)

31

VIII.AdvancedGraphics  WhilethebaseinstallationofRcontainsmanyways

tographdata,advancedusersmaywanttoconsider usingthepackagesggplot2 and/orlattice. ggplot2,forexample,allowsyoutomakespatial maps.  Therearemany,manypackagesyoucaninstallto creategraphswithR,but,foreconomists,simplicity andclarityarekey.

(c)MarkV.Siegler(Donotciteorcirculate)

32

16

InClimbingIncomeLadder,LocationMatters Theoddsofrisingtoanotherincomelevelarenotablylowincertaincities,like AtlantaandCharlotte,andhigherinNewYork,Boston,andSanFrancisco.

©MarkV.Siegler(Donotciteorcirculate)

33

IX.AFewWordsAboutPowerPoint  Followthe“8by10”Rule  Nomorethaneightlinesperslide(excludingtitle)  Nomorethantenwordsperline  Donotshowonelineatatimeonaslide (Thisisreallyannoyingtoyouraudience)  Avoidanimations,particularlyridiculousones.  FollowtheTwo‐FontRule  Nomorethantwofontsperpresentation (c)MarkV.Siegler(Donotciteorcirculate)

34

17

IX.AFewWordsAboutPowerPoint  ThePowerPointsareNOTthePresentation  Yourwordsandactionsarethepresentation  PowerPointcanhelp(insmalldoses)  PowerPointshouldn’tdominate  Oneslideeverytwoorthreeminutesatthe

maximum  Don’tjustreadyourslides!!!

(c)MarkV.Siegler(Donotciteorcirculate)

35

18...