Muenchen R for SAS and SPSS Users

2. Auflage 2011
ISBN: 978-1-4614-0685-3
Verlag: Springer
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, 707 Seiten

Reihe: Statistics and Computing

R is a powerful and free software system for data analysis and graphics, with over 1,200 add-on packages available. This book introduces R using SAS and SPSS terms with which you are already familiar. It demonstrates which of the add-on packages are most like SAS and SPSS and compares them to R's built-in functions. It steps through over 30 programs written in all three packages, comparing and contrasting the packages' differing approaches. The programs and practice datasets are available for download.
The glossary defines over 50 R terms using SAS/SPSS jargon and again using R jargon. The table of contents and the index allow you to find equivalent R functions by looking up both SAS statements and SPSS commands. When finished, you will be able to import data, manage and transform it, create publication quality graphics, and perform basic statistical analyses. 
This new edition has updated programming, an expanded index, and even more statistical methods covered in over 25 new sections.

Robert A. Muenchen is the manager of the Statistical Consulting Center at the University of Tennessee and has 28 years of experience as a consulting statistician. He has served on the advisory boards of SPSS Inc. and the Statistical Graphics Corporation.

Autoren/Hrsg.

Muenchen, Robert A.

Inhaltsverzeichnis

1;Preface;6
2;Contents;12
3;List of Tables;24
4;List of Figures;26
5;1 Introduction;30
5.1;1.1 Overview;30
5.2;1.2 Why Learn R?;31
5.3;1.3 Is R Accurate?;32
5.4;1.4 What About Tech Support?;33
5.5;1.5 Getting Started Quickly;34
5.6;1.6 The Five Main Parts of SAS and SPSS;34
5.7;1.7 Our Practice Data Sets;36
5.8;1.8 Programming Conventions;37
5.9;1.9 Typographic Conventions;38
6;2 Installing and Updating R;39
6.1;2.1 Installing Add-on Packages;39
6.2;2.2 Loading an Add-on Package;41
6.3;2.3 Updating Your Installation;43
6.4;2.4 Uninstalling R;45
6.5;2.5 Uninstalling a Package;45
6.6;2.6 Choosing Repositories;46
6.7;2.7 Accessing Data in Packages;46
7;3 Running R;49
7.1;3.1 Running R Interactively on Windows;49
7.2;3.2 Running R Interactively on Macintosh;52
7.3;3.3 Running R Interactively on Linux or UNIX;54
7.4;3.4 Running Programs That Include Other Programs;56
7.5;3.5 Running R in Batch Mode;57
7.6;3.6 Running R in SAS and WPS;58
7.6.1;3.6.1 SAS/IML Studio;58
7.6.2;3.6.2 A Bridge to R;59
7.6.3;3.6.3 The SAS X Command;59
7.6.4;3.6.4 Running SAS and R Sequentially;60
7.6.5;3.6.5 Example Program Running R from Within SAS;60
7.7;3.7 Running R in SPSS;61
7.7.1;3.7.1 Example Program Running R from Within SPSS;65
7.8;3.8 Running R in Excel;65
7.9;3.9 Running R from Within Text Editors;67
7.10;3.10 Integrated Development Environments;68
7.10.1;3.10.1 Eclipse;68
7.10.2;3.10.2 JGR;69
7.10.3;3.10.3 RStudio;70
7.11;3.11 Graphical User Interfaces;70
7.11.1;3.11.1 Deducer;71
7.11.2;3.11.2 R Commander;74
7.11.3;3.11.3 rattle;76
7.11.4;3.11.4 Red-R;79
8;4 Help and Documentation;81
8.1;4.1 Starting Help;81
8.2;4.2 Examples in Help Files;83
8.3;4.3 Help for Functions That Call Other Functions;85
8.4;4.4 Help for Packages;85
8.5;4.5 Help for Data Sets;86
8.6;4.6 Books and Manuals;86
8.7;4.7 E-mail Lists;86
8.8;4.8 Searching the Web;87
8.9;4.9 Vignettes;88
8.10;4.10 Demonstrations;88
9;5 Programming Language Basics;89
9.1;5.1 Introduction;89
9.2;5.2 Simple Calculations;90
9.3;5.3 Data Structures;91
9.3.1;5.3.1 Vectors;91
9.3.2;5.3.2 Factors;96
9.3.3;5.3.3 Data Frames;102
9.3.4;5.3.4 Matrices;106
9.3.5;5.3.5 Arrays;110
9.3.6;5.3.6 Lists;111
9.4;5.4 Saving Your Work;116
9.5;5.5 Comments to Document Your Programs;118
9.6;5.6 Comments to Document Your Objects;119
9.7;5.7 Controlling Functions (Procedures);120
9.7.1;5.7.1 Controlling Functions with Arguments;120
9.7.2;5.7.2 Controlling Functions with Objects;123
9.7.3;5.7.3 Controlling Functions with Formulas;124
9.7.4;5.7.4 Controlling Functions with an Object's Class;124
9.7.5;5.7.5 Controlling Functions with Extractor Functions;127
9.8;5.8 How Much Output There?;128
9.9;5.9 Writing Your Own Functions (Macros);133
9.10;5.10 Controlling Program Flow;135
9.11;5.11 R Program Demonstrating Programming Basics;136
10;6 Data Acquisition;143
10.1;6.1 Manual Data Entry Using the R Data Editor;143
10.2;6.2 Reading Delimited Text Files;145
10.2.1;6.2.1 Reading Comma-Delimited Text Files;146
10.2.2;6.2.2 Reading Tab-Delimited Text Files;148
10.2.3;6.2.3 Reading Text from a Web Site;149
10.2.4;6.2.4 Reading Text from the Clipboard;150
10.2.5;6.2.5 Missing Values for Character Variables;150
10.2.6;6.2.6 Trouble with Tabs;152
10.2.7;6.2.7 Skipping Variables in Delimited Text Files;153
10.2.8;6.2.8 Reading Character Strings;154
10.2.9;6.2.9 Example Programs for Reading Delimited Text Files SAS Program for Reading Delimited Text Files;154
10.3;6.3 Reading Text Data Within a Program;157
10.3.1;6.3.1 The Easy Approach;158
10.3.2;6.3.2 The More General Approach;159
10.3.3;6.3.3 Example Programs for Reading Text Data Within a Program SAS Program for Reading Text Data Within a Program;160
10.4;6.4 Reading Multiple Observations per Line;162
10.4.1;6.4.1 Example Programs for Reading Multiple Observations per Line Example SAS Program for Reading Multiple Observations per Line;164
10.5;6.5 Reading Data from the Keyboard;166
10.6;6.6 Reading Fixed-Width Text Files, One Record per Case;166
10.6.1;6.6.1 Reading Data Using Macro Substitution;169
10.6.2;6.6.2 Example Programs for Reading Fixed-Width Text Files, One Record per Case;170
10.7;6.7 Reading Fixed-Width Text Files, Two or More Records per Case;171
10.7.1;6.7.1 Example Programs to Read Fixed-Width Text Files with Two Records per Case SAS Program to Read Two Records per Case;173
10.8;6.8 Reading Excel Files;174
10.8.1;6.8.1 Example Programs for Reading Excel Files SAS Program for Reading Excel Files;175
10.9;6.9 Reading from Relational Databases;176
10.10;6.10 Reading Data from SAS;177
10.10.1;6.10.1 Example Programs to Write Data from SAS and Read It into R;178
10.11;6.11 Reading Data from SPSS;179
10.11.1;6.11.1 Example Programs for Reading Data from SPSS;180
10.12;6.12 Writing Delimited Text Files;181
10.12.1;6.12.1 Example Programs for Writing Delimited Text Files SAS Program for Writing Delimited Text Files;182
10.13;6.13 Viewing a Text File;184
10.14;6.14 Writing Excel Files;184
10.14.1;6.14.1 Example Programs for Writing Excel Files SAS Program for Writing Excel Files;185
10.15;6.15 Writing to Relational Databases;186
10.16;6.16 Writing Data to SAS and SPSS;186
10.16.1;6.16.1 Example Programs to Write Data to SAS and SPSS;187
11;7 Selecting Variables;189
11.1;7.1 Selecting Variables in SAS and SPSS;189
11.2;7.2 Subscripting;190
11.3;7.3 Selecting Variables by Index Number;191
11.4;7.4 Selecting Variables by Column Name;194
11.5;7.5 Selecting Variables Using Logic;195
11.6;7.6 Selecting Variables by String Search (varname: or varname1-varnameN);197
11.7;7.7 Selecting Variables Using $ Notation;200
11.8;7.8 Selecting Variables by Simple Name;200
11.8.1;7.8.1 The attach Function;201
11.8.2;7.8.2 The with Function;202
11.8.3;7.8.3 Using Short Variable Names in Formulas;202
11.9;7.9 Selecting Variables with the subset Function;203
11.10;7.10 Selecting Variables by List Subscript;204
11.11;7.11 Generating Indices A to Z from Two Variable Names;204
11.11.1;7.11.1 Selecting Numeric or Character Variables;205
11.12;7.12 Saving Selected Variables to a New Data Set;208
11.13;7.13 Example Programs for Variable Selection;208
11.13.1;7.13.1 SAS Program to Select Variables;209
11.13.2;7.13.2 SPSS Program to Select Variables;209
11.13.3;7.13.3 R Program to Select Variables;210
12;8 Selecting Observations;215
12.1;8.1 Selecting Observations in SAS and SPSS;215
12.2;8.2 Selecting All Observations;216
12.3;8.3 Selecting Observations by Index Number;217
12.4;8.4 Selecting Observations Using Random Sampling;219
12.5;8.5 Selecting Observations by Row Name;221
12.6;8.6 Selecting Observations Using Logic;222
12.7;8.7 Selecting Observations by String Search;226
12.8;8.8 Selecting Observations with the subset Function;228
12.9;8.9 Generating Indices A to Z from Two Row Names;228
12.10;8.10 Variable Selection Methods with No Counterpart for Selecting Observations;229
12.11;8.11 Saving Selected Observations to a New Data Frame;229
12.12;8.12 Example Programs for Selecting Observations;230
12.12.1;8.12.1 SAS Program to Select Observations;230
12.12.2;8.12.2 SPSS Program to Select Observations;231
12.12.3;8.12.3 R Program to Select Observations;231
13;9 Selecting Variables and Observations;237
13.1;9.1 The subset Function;237
13.2;9.2 Subscripting with Logical Selections and Variable Names;239
13.3;9.3 Using Names to Select Both Observations and Variables;240
13.4;9.4 Using Numeric Index Values to Select Both Observations and Variables;241
13.5;9.5 Using Logic to Select Both Observations and Variables;241
13.6;9.6 Saving and Loading Subsets;242
13.7;9.7 Example Programs for Selecting Variables and Observations;243
13.7.1;9.7.1 SAS Program for Selecting Variables and Observations;243
13.7.2;9.7.2 SPSS Program for Selecting Variables and Observations;243
13.7.3;9.7.3 R Program for Selecting Variables and Observations;244
14;10 Data Management;246
14.1;10.1 Transforming Variables;246
14.1.1;10.1.1 Example Programs for Transforming Variables SAS Program for Transforming Variables;250
14.2;10.2 Procedures or Functions? The apply Function Decides;252
14.2.1;10.2.1 Applying the mean Function;252
14.2.2;10.2.2 Finding N or NVALID;256
14.2.3;10.2.3 Standardizing and Ranking Variables;258
14.2.4;10.2.4 Applying Your Own Functions;260
14.2.5;10.2.5 Example Programs for Applying Statistical Functions SAS Program for Applying Statistical Functions;261
14.3;10.3 Conditional Transformations;264
14.3.1;10.3.1 The ifelse Function;264
14.3.2;10.3.2 Cutting Functions;268
14.3.3;10.3.3 Example Programs for Conditional Transformations SAS Program for Conditional Transformations;269
14.4;10.4 Multiple Conditional Transformations;273
14.4.1;10.4.1 Example Programs for Multiple Conditional Transformations SAS Program for Multiple Conditional Transformations;275
14.5;10.5 Missing Values;277
14.5.1;10.5.1 Substituting Means for Missing Values;279
14.5.2;10.5.2 Finding Complete Observations;280
14.5.3;10.5.3 When \99" Has Meaning;281
14.5.4;10.5.4 Example Programs to Assign Missing Values SAS Program to Assign Missing Values;282
14.6;10.6 Renaming Variables (and Observations);285
14.6.1;10.6.1 Advanced Renaming Examples;287
14.6.2;10.6.2 Renaming by Index;288
14.6.3;10.6.3 Renaming by Column Name;289
14.6.4;10.6.4 Renaming Many Sequentially Numbered Variable Names;290
14.6.5;10.6.5 Renaming Observations;291
14.6.6;10.6.6 Example Programs for Renaming Variables;291
14.7;10.7 Recoding Variables;295
14.7.1;10.7.1 Recoding a Few Variables;296
14.7.2;10.7.2 Recoding Many Variables;296
14.7.3;10.7.3 Example Programs for Recoding Variables SAS Program for Recoding Variables;299
14.8;10.8 Indicator or Dummy Variables;301
14.8.1;10.8.1 Example Programs for Indicator or Dummy Variables SAS Program for Indicator or Dummy Variables;304
14.9;10.9 Keeping and Dropping Variables;306
14.9.1;10.9.1 Example Programs for Keeping and Dropping Variables SAS Program for Keeping and Dropping Variables;307
14.10;10.10 Stacking/Concatenating/Adding Data Sets;308
14.10.1;10.10.1 Example Programs for Stacking/Concatenating/Adding Data Sets SAS Program for Stacking/Concatenating/Adding Data Sets;310
14.11;10.11 Joining/Merging Data Sets;312
14.11.1;10.11.1 Example Programs for Joining/Merging Data Sets SAS Program for Joining/Merging Data Sets;315
14.12;10.12 Creating Summarized or Aggregated Data Sets;317
14.12.1;10.12.1 The aggregate Function;317
14.12.2;10.12.2 The tapply Function;319
14.12.3;10.12.3 Merging Aggregates with Original Data;321
14.12.4;10.12.4 Tabular Aggregation;323
14.12.5;10.12.5 The plyr and reshape2 Packages;325
14.12.6;10.12.6 Comparing Summarization Methods;325
14.12.7;10.12.7 Example Programs for Aggregating/Summarizing Data SAS Program for Aggregating/Summarizing Data;326
14.13;10.13 By or Split-File Processing;329
14.13.1;10.13.1 Example Programs for By or Split-File Processing SAS Program for By or Split-File processing;333
14.14;10.14 Removing Duplicate Observations;335
14.14.1;10.14.1 Completely Duplicate Observations;335
14.14.2;10.14.2 Duplicate Keys;338
14.14.3;10.14.3 Example Programs for Removing Duplicates SAS Program for Removing Duplicates;338
14.15;10.15 Selecting First or Last Observations per Group;341
14.15.1;10.15.1 Example Programs for Selecting Last Observation per Group SAS Program for Selecting Last Observation per Group;344
14.16;10.16 Transposing or Flipping Data Sets;346
14.16.1;10.16.1 Example Programs for Transposing or Flipping Data Sets SAS Program for Transposing or Flipping Data Sets;349
14.17;10.17 Reshaping Variables to Observations and Back;351
14.17.1;10.17.1 Summarizing/Aggregating Data Using reshape2;355
14.17.2;10.17.2 Example Programs for Reshaping Variables to Observations and Back;357
14.18;10.18 Sorting Data Frames;360
14.18.1;10.18.1 Example Programs for Sorting Data Sets SAS Program for Sorting Data;363
14.19;10.19 Converting Data Structures;365
14.19.1;10.19.1 Converting from Logical to Numeric Index and Back;368
14.20;10.20 Character String Manipulations;369
14.20.1;10.20.1 Example Programs for Character String Manipulation SAS Program for Character String Manipulation;376
14.21;10.21 Dates and Times;381
14.21.1;10.21.1 Calculating Durations;385
14.21.2;10.21.2 Adding Durations to Date-Time Variables
;389
14.21.3;10.21.3 Accessing Date-Time Elements
;389
14.21.4;10.21.4 Creating Date-Time Variables from Elements
;390
14.21.5;10.21.5 Logical Comparisons with Date-Time Variables
;391
14.21.6;10.21.6 Formatting Date-Time Output
;391
14.21.7;10.21.7 Two-Digit Years;392
14.21.8;10.21.8 Date-Time Conclusion
;393
14.21.9;10.21.9 Example Programs for Dates and Times SAS Program for Dates and Times;393
15;11 Enhancing Your Output;401
15.1;11.1 Value Labels or Formats (and Measurement Level);401
15.1.1;11.1.1 Character Factors;402
15.1.2;11.1.2 Numeric Factors;404
15.1.3;11.1.3 Making Factors of Many Variables;406
15.1.4;11.1.4 Converting Factors to Numeric or Character Variables;409
15.1.5;11.1.5 Dropping Factor Levels;410
15.1.6;11.1.6 Example Programs for Value Labels SAS Program to Assign Value Labels;411
15.1.7;11.1.7 R Program to Assign Value Labels and Factor Status;412
15.2;11.2 Variable Labels;415
15.2.1;11.2.1 Other Packages That Support Variable Labels;419
15.2.2;11.2.2 Example Programs for Variable Labels SAS Program for Variable Labels;419
15.3;11.3 Output for Word Processing and Web Pages;421
15.3.1;11.3.1 The xtable Package;422
15.3.2;11.3.2 Other Options for Formatting Output;424
15.3.3;11.3.3 Example Program for Formatting Output;424
16;12 Generating Data;426
16.1;12.1 Generating Numeric Sequences;427
16.2;12.2 Generating Factors;428
16.3;12.3 Generating Repetitious Patterns (Not Factors);429
16.4;12.4 Generating Values for Reading Fixed-Width Files;430
16.5;12.5 Generating Integer Measures;431
16.6;12.6 Generating Continuous Measures;433
16.7;12.7 Generating a Data Frame;434
16.8;12.8 Example Programs for Generating Data;436
16.8.1;12.8.1 SAS Program for Generating Data;436
16.8.2;12.8.2 SPSS Program for Generating Data;437
16.8.3;12.8.3 R Program for Generating Data;438
17;13 Managing Your Files and Workspace;442
17.1;13.1 Loading and Listing Objects;442
17.2;13.2 Understanding Your Search Path;446
17.3;13.3 Attaching Data Frames;447
17.4;13.4 Loading Packages;449
17.5;13.5 Attaching Files;451
17.6;13.6 Removing Objects from Your Workspace;452
17.7;13.7 Minimizing Your Workspace;455
17.8;13.8 Setting Your Working Directory;455
17.9;13.9 Saving Your Workspace;456
17.9.1;13.9.1 Saving Your Workspace Manually;456
17.9.2;13.9.2 Saving Your Workspace Automatically;456
17.9.3;13.9.3 Getting Operating Systems to Show You .RData Files;457
17.9.4;13.9.4 Organizing Projects with Windows Shortcuts;457
17.10;13.10 Saving Your Programs and Output;458
17.11;13.11 Saving Your History;458
17.12;13.12 Large Data Set Considerations;460
17.13;13.13 Example R Program for Managing Files and Workspace;460
18;14 Graphics Overview;465
18.1;14.1 Dynamic Visualization;465
18.2;14.2 SAS/GRAPH;466
18.3;14.3 SPSS Graphics;466
18.4;14.4 R Graphics;467
18.5;14.5 The Grammar of Graphics;468
18.6;14.6 Other Graphics Packages;469
18.7;14.7 Graphics Archives;469
18.8;14.8 Graphics Demonstrations;469
18.9;14.9 Graphics Procedures and Graphics Systems;471
18.10;14.10 Graphics Devices;472
19;15 Traditional Graphics;475
19.1;15.1 The plot Function;475
19.2;15.2 Bar Plots;477
19.2.1;15.2.1 Bar Plots of Counts;477
19.2.2;15.2.2 Bar Plots for Subgroups of Counts;481
19.2.3;15.2.3 Bar Plots of Means;482
19.3;15.3 Adding Titles, Labels, Colors, and Legends;483
19.4;15.4 Graphics Parameters and Multiple Plots on a Page;486
19.5;15.5 Pie Charts;489
19.6;15.6 Dot Charts;490
19.7;15.7 Histograms;490
19.7.1;15.7.1 Basic Histograms;491
19.7.2;15.7.2 Histograms Stacked;493
19.7.3;15.7.3 Histograms Overlaid;494
19.8;15.8 Normal QQ Plots;499
19.9;15.9 Strip Charts;500
19.10;15.10 Scatter and Line Plots;504
19.10.1;15.10.1 Scatter Plots with Jitter;507
19.10.2;15.10.2 Scatter Plots with Large Data Sets;507
19.10.3;15.10.3 Scatter Plots with Lines;510
19.10.4;15.10.4 Scatter Plots with Linear Fit by Group;511
19.10.5;15.10.5 Scatter Plots by Group or Level (Coplots);513
19.10.6;15.10.6 Scatter Plots with Con dence Ellipse;513
19.10.7;15.10.7 Scatter Plots with Con dence and Prediction Intervals;514
19.10.8;15.10.8 Plotting Labels Instead of Points;520
19.10.9;15.10.9 Scatter Plot Matrices;522
19.11;15.11 Dual-Axis Plots;524
19.12;15.12 Box Plots;526
19.13;15.13 Error Bar Plots;529
19.14;15.14 Interaction Plots;529
19.15;15.15 Adding Equations and Symbols to Graphs;529
19.16;15.16 Summary of Graphics Elements and Parameters;531
19.17;15.17 Plot Demonstrating Many Modi cations;531
19.18;15.18 Example Traditional Graphics Programs;532
19.18.1;15.18.1 SAS Program for Traditional Graphics;534
19.18.2;15.18.2 SPSS Program for Traditional Graphics;534
19.18.3;15.18.3 R Program for Traditional Graphics;535
20;16 Graphics with ggplot2;545
20.1;16.1 Introduction;545
20.1.1;16.1.1 Overview of qplot and ggplot;546
20.1.2;16.1.2 Missing Values;548
20.1.3;16.1.3 Typographic Conventions;549
20.2;16.2 Bar Plots;550
20.3;16.3 Pie Charts;552
20.4;16.4 Bar Plots for Groups;554
20.5;16.5 Plots by Group or Level;555
20.6;16.6 Presummarized Data;556
20.7;16.7 Dot Charts;558
20.8;16.8 Adding Titles and Labels;559
20.9;16.9 Histograms and Density Plots;560
20.9.1;16.9.1 Histograms;560
20.9.2;16.9.2 Density Plots;561
20.9.3;16.9.3 Histograms with Density Overlaid;562
20.9.4;16.9.4 Histograms for Groups, Stacked;563
20.9.5;16.9.5 Histograms for Groups, Overlaid;564
20.10;16.10 Normal QQ Plots;564
20.11;16.11 Strip Plots;565
20.12;16.12 Scatter Plots and Line Plots;568
20.12.1;16.12.1 Scatter Plots with Jitter;571
20.12.2;16.12.2 Scatter Plots for Large Data Sets;572
20.12.3;16.12.3 Scatter Plots with Fit Lines;577
20.12.4;16.12.4 Scatter Plots with Reference Lines;579
20.12.5;16.12.5 Scatter Plots with Labels Instead of Points;581
20.12.6;16.12.6 Changing Plot Symbols;583
20.12.7;16.12.7 Scatter Plot with Linear Fits by Group;584
20.12.8;16.12.8 Scatter Plots Faceted by Groups;585
20.12.9;16.12.9 Scatter Plot Matrix;586
20.13;16.13 Box Plots;588
20.14;16.14 Error Bar Plots;591
20.15;16.15 Geographic Maps;592
20.15.1;16.15.1 Finding and Converting Maps;597
20.16;16.16 Logarithmic Axes;598
20.17;16.17 Aspect Ratio;599
20.18;16.18 Multiple Plots on a Page;599
20.19;16.19 Saving ggplot2 Graphs to a File;601
20.20;16.20 An Example Specifying All Defaults;602
20.21;16.21 Summary of Graphics Elements and Parameters;603
20.22;16.22 Example Programs for Grammar of Graphics;604
20.22.1;16.22.1 SPSS Program for Graphics Production Language;604
20.22.2;16.22.2 R Program for ggplot2;607
21;17 Statistics;623
21.1;17.1 Scienti c Notation;623
21.2;17.2 Descriptive Statistics;624
21.2.1;17.2.1 The Deducer frequencies Function;624
21.2.2;17.2.2 The Hmisc describe Function;625
21.2.3;17.2.3 The summary Function;627
21.2.4;17.2.4 The table Function and Its Relatives;628
21.2.5;17.2.5 The mean Function and Its Relatives;630
21.3;17.3 Cross-Tabulation;631
21.3.1;17.3.1 The CrossTable Function;631
21.3.2;17.3.2 The table and chisq.test Functions;632
21.4;17.4 Correlation;636
21.4.1;17.4.1 The cor Function;638
21.5;17.5 Linear Regression;640
21.5.1;17.5.1 Plotting Diagnostics;644
21.5.2;17.5.2 Comparing Models;645
21.5.3;17.5.3 Making Predictions with New Data;646
21.6;17.6 t-Test: Independent Groups;646
21.7;17.7 Equality of Variance;648
21.8;17.8 t-Test: Paired or Repeated Measures;649
21.9;17.9 Wilcoxon{Mann{Whitney Rank Sum: Independent Groups;650
21.10;17.10 Wilcoxon Signed-Rank Test: Paired Groups;651
21.11;17.11 Sign Test: Paired Groups;652
21.12;17.12 Analysis of Variance;654
21.13;17.13 Sums of Squares;657
21.14;17.14 The Kruskal{Wallis Test;659
21.15;17.15 Example Programs for Statistical Tests;661
21.15.1;17.15.1 SAS Program for Statistical Tests;661
21.15.2;17.15.2 SPSS Program for Statistical Tests;663
21.15.3;17.15.3 R Program for Statistical Tests;665
22;18 Conclusion;670
23;References;685
24;Index;690