Re: [R] compare odds ratios
You could try a test for heterogeneity of the odds ratios, usually part of a Mantel-Haenszel analysis, with each test as a stratum. Also, the field of meta-analysis has tests for heterogeneity of estimates. Both are covered in Rothman and Greenland's Modern Epidemiology (1998) text, Chapters 15 and 32 respectively. Daniel Smith Environmental Health Investigations Branch California Department of Health Services -Original Message- Message: 43 Date: Tue, 27 Jun 2006 11:22:14 -0700 (PDT) From: array chip [EMAIL PROTECTED] Subject: Re: [R] compare odds ratios To: r-help@stat.math.ethz.ch Message-ID: [EMAIL PROTECTED] Content-Type: text/plain; charset=iso-8859-1 Hi dear all, I haven't heard any suggestions on how to tackle the problem in my previous email yet. I searched on google and was not getting any useful information yet. I did get someone from google groups suggesting Cockran Mantel Haenszel test with each subject as the stratum. But as far as I understand, CMH test is to test whether the common odds ratio (assuming odds ratios across stratum are equal) is equal to 1, not really the question I was asking which was whether the 2 odds ratios were equal (doesn't matter if they are equal to 1). Also, someone suggested loglinear regression, but I am not sure either how to set things up for my problem. One clarification to my original email: the 2 diagnostic tests were performed on the set set of patients, the issue here how to test whether the 2 odds ratios for the 2 diagnostic tests are equal. Here is a hypothetical dataset, for example: dat- cbind(disease=sample(c(rep(1,15),rep(0,20))),test1=sample(c(rep(1,11),re p( 0,24))),test2=sample(c(rep(1,14),rep(0,21 Hope some statistical experts would guide me some directions. Many thanks ** __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
Re: [R] R Graphs in Powerpoint
I've tried several methods in OS X, and here's what works best for me. Save the R graphic as a PDF file. Open it with Apple's Preview application, and save it as a PNG file. The resulting .png file can be inserted into MS Word or PowerPoint, can be resized, and looks good on either OS X or Windows. There are other programs available for translating the pdf file to png (like the shareware application Graphic Converter), but I've found that Preview produces the best results. Daniel Smith Environmental Health Investigations Branch California Dept of Health Services -Original Message- Date: Mon, 31 Oct 2005 15:14:06 -0800 From: Jarrett Byrnes [EMAIL PROTECTED] Subject: [R] R Graphs in Powerpoint To: r-help@stat.math.ethz.ch Message-ID: [EMAIL PROTECTED] Content-Type: text/plain; charset=US-ASCII; format=flowed Hey, all. Quick question. I'm attempting to use some of the great graphs generated in R for an upcoming talk that I'm writing in Powerpoint. Copying and pasting (I'm using OSX) yields graphs that look great in Powerpoint - until I resize them. Then fonts, points, and lines all become quite pixelated and blurry. Even if I size the window properly first, and then copy and paste in the graph, when I then view the slideshow, the graphs come out pixelated and blurry. Is there any good solution to this, or is this some fundamental incompatibility that I can't get around? -Jarrett __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
[R] RE: question about spatial correlation with Xs and Ys
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]
Sent: Tuesday, July 01, 2003 3:09 AM
To: [EMAIL PROTECTED]
Subject: R-help Digest, Vol 5, Issue 1
At 18:48 30/06/2003, Martin Wegmann wrote:
hello,
I want to do a test for spatial correlation.
I tried it with geary.test() but I don't understand the required input.
x= a numeric vector the same length as the neighbours list in listw (my
sampled data, I assume)
listw= a listw object created for example by nb2listw (well when I check
nb2listw() I get to neighbours - an object of class nb - but I couldn't
figure out, what nb is or how I create such a class
with sp.mantel.mc {spdep} I have the same problem: listw created by
nb2listw
isn't there a more straight forward method ;-) to check for spatial
correlation? like x and y coordinates plus my sampled data?
Check out the notes from a short course in Spatial Epidemiology by Best et
al., at http://stats.ma.ic.ac.uk/~ngb30/. They have S-plus code to run
Moran's I and Tango's test for spatial correlation that use disease counts
in small areas and their X and Y coordinates.
Daniel Smith, Dr.P.H.
Environmental Health Investigations Branch
California Department of Health Services
1515 Clay Street, Suite 1700
Oakland, CA 94612
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