search for: carcinogens

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

...y 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. We lead collaborative research teams that include top computer scientists, statisticians, and other scientists at Brown, Harvard, UC Berkeley, and elsewhere. We seek a research assistant or staff scientist with experience in computer science, data analysi...

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

A time series text with a title that seems designed to hide its wide scope is: Forecasting with Exponential Smoothing The State Space Approach Hyndman, R.J., Koehler, A.B., Ord, J.K., Snyder, R.D. Springer 2009. This book is actually an excellent overview of time series theory, ARIMA as well as state space. It is of course, in part, a manual for the forecast and other packages in what has been