similar to: Bias in sample - Logistic Regression

Dear Listers, Sorry for bothering you on Thxgiving. I am just curious how to build a saturated model for logistic regression or other kinds of regression. Thank you so much! wensui

Hi! I am working on scorecard model and I have arrived at the regression equation. I have used logistic regression using R. My question is how do I validate this model? I do have hold out sample of 5000 customers. Please guide me. Problem is I had never used Logistic regression earlier neither I am used to credit scoring models. Thanks in advance Maithili

I have to the treatment effect base on the observational data.And the treatment variable is multinomial rather than binary.Because the treatment assignment is not random,so the selection-bias exists.Under this condition,what's the best way to estimate the treatment effect? I know that if the treatment is binary,I can use propensity score matching using MatchIt package.But what about

Dear All, My question is more a statistical question than a R question. The reason I am posting here is that there are lots of excellent statistician on this list, who can always give me good advices. Per my understanding, the purpose of propensity score is to reduce the bias while estimating the treatment effect and its implementation is a 2-stage model. 1) First of all, if we assume that T =

Dear Lister, If I have a list of number, say x<-c(0.1, 0.5, 0.6...), how to use a for() to loop through each number in x one by one? Thank you so much! wensui [[alternative HTML version deleted]]

Right now, I am using SAS and S+/R. As a new year resolution, I am planning to learn a scripting language. from statisticians' point of view, which scripting language is worth to learn, perl, python, or any other recommendation? (Most likely, I will be learning it in windows.) Since I am not in research, I will prefer one widely used in industry and related to statistical work. if you

Good morning, dear listers I am wondering if you could recommend a good tutorial / book for r scripting. thank you so much in advance! WenSui Liu Credit Risk Manager, 53 Bancorp wensui.liu at 53.com 513-295-4370

Dear Lister, plot() is using the data range as the default limits of yaxis. Is there any way I can change the limits? I just look at the help of plot() and par() and couldn't find answers. Thanks. -- WenSui Liu (http://spaces.msn.com/statcompute/blog) Senior Decision Support Analyst Health Policy and Clinical Effectiveness Cincinnati Children Hospital Medical Center

Dear All, I finally have chance to have R install on our unix server. However, the system admin asked me if I prefer command-line or gui interface. I have experience with R on linux before but never use R on unix. Here are my questions that I need you guys help. 1) is there a good gui for R/unix like we do for windows and mac? 2) if the answer for 1) is yes, which one is better interms of

I remember in one slide of Prof. Ripley's presentation overhead, he said the most popular data analysis software is excel. So is there any resource or tutorial on this topic? Thank you so much!

Dear Lister, I understand merge() can be used to join 2 data frames based on 1 variable. But how about merge based on more than 2 variables? Thank you so much! -- WenSui Liu (http://spaces.msn.com/statcompute/blog) Senior Decision Support Analyst Health Policy and Clinical Effectiveness Cincinnati Children Hospital Medical Center [[alternative HTML version deleted]]

Dear All, Is there a emacs/xemacs for unix without compiling it? If it is possible, I prefer something that I can use immediately after putting it on the unix server. Is it possible or am I too stupid to ask this kind of question? Thanks for your insight! -- =============================== WenSui Liu ChoicePoint Precision Marketing Phone: 678-893-9457 Email : wensui.liu at choicepoint.com Blog

I checked GlmmML package. However, it can only do binomial and poisson distribution. How about others such as gamma or neg binomial? Thank you so much! wensui

Good morning, dear listers I am wondering how to do string evaluation such that model <- glm(Y ~ [STRING], data = mydata) where STRING <- "x1 + x2 + x3" It is very doable in other language such as SAS. Thank you so much for your insight!

I really have headache when I do google search for information about "R". Any tricks or tips? thx.

I like R more than SAS. My job is doing research on clinical trial. But I was told that FDA only accepts the result from SAS. Is that true? TOO BAD. [[alternate HTML version deleted]]

Dear Listers, I've been a big fan of R since graduate school. After working in the industry for years, I haven't had many opportunities to use R and am mainly using SAS. However, I am still forcing myself really hard to stay close to R by reading R-help and books and writing R code by myself for fun. But by and by, I start realizing I have hard time to keep up with R and am afraid that I

Hi R-experts, I have data from four conditions of an experiment. I tried to create four subsets of the data with read.table, for example, read.table("Experiment.csv",subset=(condition=="1")) . I found a similar post in the archive, but the answer to that post was no. Any new ideas about reading subsets of data with read.table? Thanks! Feng [[alternative HTML version

Latex and R are really cool stuff. I am just wondering how they are used in industry. But based on my own experience, very rare. Why? How about the opinion of other listers? Thanks.

Sometimes, it is too costly to read the whole data file into R. I am looking for solution in scan() and read.Lines() but don't they work. Thank you so much! -- ============================== WenSui Liu Acquisition Risk, Chase Blog : statcompute.spaces.live.com Tough Times Never Last. But Tough People Do. - Robert Schuller