Re: Combinometrics
In article [EMAIL PROTECTED], Jerry Dallal [EMAIL PROTECTED] wrote: Herman Rubin wrote: I also doubt whether learning to compute answers gives any insight into the concepts, except for those with good research potential, and even there it tends to confuse. It depends on what learning to compute means. (*I'm* saying this in repsonse to a comment from Prf. Rubin?!) Consider exp(i pi). I can compute it by using Euler's rule or by viewing it as the pi radians rotation of a rod of unit length in the imaginary plane. The second is not a means of computing, but of interpretation. Or consider the variance. I can compute it by using the desk calculator algorithm or by summing the squares of deviations. Knowing how to do it, and why, is not the same as the actual process of computing. I would go so far as to say that there is little, if any, point about computing the SAMPLE mean and the SAMPLE standard variance before understanding that of the population mean. Even population here is a bad term, as it implies that sampling without replacement is to be used, which is not the same as that of numerical functions of observations from arbitrary probability models. Even expectations should be done on a sample space, and it should be shown, or at least pointed out, that which equivalent formulation is used leads to the same results, including using the distribution as a particular one of these. If learning to compute means simply that one is given a formula--any formula--that is to be used without any thought of its origins, I agree. OTOH, thoughts about the method of computation can often lead to important insights. It is SOMETIMES the case that the procedure, not the method used to implement it, can do this. Setting up expectation on sample spaces makes additivity trivial; pointing out the equivalence of different representations makes expectation and variance of the binomial and hypergeometric quite easy, natural, and understandable. However, doing it using combinatorics provides no insight whatever, nor does using the cdf or pdf add much insight to anything about the concepts. Also, it is not necessary to introduce bivariate distributions to develop covariance, or its properties. Expectations of products are expectations, and simple algebra still works. -- This address is for information only. I do not claim that these views are those of the Statistics Department or of Purdue University. Herman Rubin, Dept. of Statistics, Purdue Univ., West Lafayette IN47907-1399 [EMAIL PROTECTED] Phone: (765)494-6054 FAX: (765)494-0558 = Instructions for joining and leaving this list and remarks about the problem of INAPPROPRIATE MESSAGES are available at http://jse.stat.ncsu.edu/ =
Course: R Fundamentals and Programming Techniques by Prof. Doug Bates, July 18-20, 2001
XLSolutions Corporation (www.xlsolutions-corp.com) is pleased to announce a three-day R course, R Fundamentals and Programming Techniques, presented by Professor Doug Bates. This special three-day R course is designed for those who want to learn to write R programs to accomplish typical data-processing tasks, including creating graphics. The course will give beginners a strong foundation for becoming a versatile R programmer, and will expose experienced users to skills that make a better R programmer. R is a freely available implementation of the S language and environment, for statistical computing and graphics similar to the commercial S-PLUS. You can download a copy of R software (Windows, Mac, Unix Linux) from http://cran.r-project.org. Course Description: This three-day R course focuses on a broad spectrum of topics, from reading raw data to a comparison of R and SAS. We will learn the essentials of data manipulation, graphical visualization and R programming. We will explore statistical data analysis tools, including graphics with data sets from areas such as Finance, Biopharm, manufacturing and E-commerce. However, participants are encouraged to bring their own data for an interactive session with the trainer. Course Outline: Day 1 · An Overview of R: Installation and Demonstration · Data Manipulation and Graphics · A Comparison of R and S-PLUS · How can R Complement SAS? Day 2 · Writing Functions · Data Mining and Statistical Modeling · Case Studies With Data from Participants Day 3 · Project Management · Techniques for Effective use of R · Connecting R to External Data Sources · Enhancing Plots Cost for 3-day course: Chicago - July 18-20, 2001. Commercial $985 Academic $875 (Includes course materials and 90 days Technical Support for R.) Registration: Email Sue Turner: [EMAIL PROTECTED] Phone: 206-686-1578 x221 Visit us: www.xlsolutions-corp.com/training.htm Course Format: This course consists of a series of short lectures with demonstrations and interactive sessions for the participants. Each student is provided with bound copies of the notes and a CD-ROM containing all examples, exercises and software used on the course. Trainer's Background: Douglas Bates is Professor of Statistics at the University of Wisconsin - Madison and a member of the R Development Core Team. He is co-author of the nonlinear modeling functions in both R and S-PLUS and a co-author of both the R and S-PLUS versions of the nlme package for fitting linear and nonlinear mixed-effects models. He has taught short courses on nonlinear regression and mixed-effects models on many occasions. He is the author with Donald G. Watts of Nonlinear Regression Analysis and Its Applications and with Jose C. Pinheiro of Mixed-effects Models in S and S-PLUS. Share Your Thoughts: Are there any additional topics you would like for this course to address? Would you like for this course to be offered in another city? Please let us know by contributing to our recommendation list: [EMAIL PROTECTED] == Three-day 18-20 July R Fundamentals and Programming Techniques. Pre-registration Form (Please email or print and fax: 206-686-1578) XLsolutions Corporation: For your Solutions needs, Consulting and Training. www.xlsolutions-corp.com Title.. First Name . Last Name Organization.. Mailing Address... . . Zip Code.. Country. Telephone... Fax ... E-mail Payment will be made by: (1) check (2) invoice (3) bank transfer -- Posted from machine3.229.245.64.virtual-space.com [64.245.229.3] (may be forged) via Mailgate.ORG Server - http://www.Mailgate.ORG = Instructions for joining and leaving this list and remarks about the problem of INAPPROPRIATE MESSAGES are available at http://jse.stat.ncsu.edu/ =
