search for: carcinogenicity

Dear R-listers, Does anybody know what is the correct source of "rats" dataset in survival package? The help gives the following information: Rat data from survival5 Description: 48 rats were injected with a carcinogen, and then randomized to either drug or placebo. The number of tumors ranges from 0 to 13; all rats were censored at 6 months after randomization.

Hi, I would like to derive p-values for pair-wise comparison (Tukey's) of effects when the response is a count. I am trying a test case where y ~ Po( lambda(x) ). x has three levels : A, B and C with lambda(x) = 10, 20 and 20 respectively. Hence, p-values for the contrast C - B should distribute uniformally. I have implemented this test case as below but do not get uniform

Research Assistant/Staff Scientist: Technology in Environmental Health (Silent Spring Institute; Boston, MA) Silent Spring Institute is a non-profit scientific research group studying the environment and health. We are a multi-disciplinary team and international leader in research on everyday exposures to hormone disruptors, tests for breast carcinogens, and environmental links to breast cancer.

Hi all, I am looking for a clever way to create the following graph using R: I got information on the shares of some subgroups over time (summing up to 1 in each year). The graph I want to create should display the development of the individual shares over time by shading rectangulars for each share in a different color. Is there a clever of doing this? Thanks for your help Stefan

...alues are uniform only when the distribution is continuous. See > > Westfall, P.H. and Troendle, J.F. (2008). Multiple Testing with > Minimal Assumptions, Biometrical Journal 50, 745-755. > > Westfall, P.H., and Soper, K.A. (2001). "Using priors to improve > multiple animal carcinogenicity tests<http://pubs.amstat.org/doi/pdfplus/10.1198/016214501753208852 >> ", Journal of the American Statistical Association 96, 827-834. > > Westfall, P.H. and Wolfinger, R.D.(1997). "Multiple Tests with > Discrete Distributions<http://www.jstor.org/stable/2684683>,&...