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...ns "step" or "stepAIC"? When would one use "mle.stepwise" versus "step/stepAIC"? Other than the references in the R-software, is there anything which discusses the use of "mle.stepwise"? Thank you kindly in advance for any insight offered. Jim Brindle

Hello, Is there anyway one can have more than 11 independent variables in a regression model? To hopefully illustrate: with 13 predictors in my model, the last 2 coefficient estimates are "NA". When I view the summary, it indicates that 2 coefficients are "not defined because of singularities". I am using the command: mod <- lm(y ~ ., data = volumes[,3:22]) I am

Hello, I am trying to understand how to utilize the "mvr" function in the pls Package of R. I am utilizing the R "pls Package" document dated 18 May 2005 as guidance. My data set consists of a 12 x 12 data frame created from reading in a table of values. I have read the data in via the command: volumes <- read.table("THA_vol.txt", header = TRUE) and then

Hello, I am guessing this is not a difficult question. But at the same time, I haven't had much luck figuring this issue out from the R documentation and help pages. How can I create superscript text in the labels of a plot? The parameter along my y-axis is volume and my desire is for the y-axis label to read "Volume (cm^3)" except with the "3" in the superscript

...nput file) display in bold the values on the y-axis since I am trying to run this code on several different sets of data. However, if the resolution to this issue requires me to manipulate the code based on the y-values in the each input file that'll work too. Thank you kindly in advance, Jim Brindle [[alternative HTML version deleted]]

Hello, I am hoping someone could shed some light into the Wilcoxon Rank Sum Test for me? In looking through Stats references, the Mann-Whitney U-test and the Wilcoxon Rank Sum Test are statistically equivalent. When using the following dataset: m <- c(2.0863,2.1340,2.1008,1.9565,2.0413,NA,NA) f <- c(1.8938,1.9709,1.8613,2.0836,1.9485,2.0630,1.9143) and the wilcox.test command as

Hello, I am hoping someone could shed some light on power calculations for me. I have two small data sets of unequal sample size after NA removal (m = 5, f = 7). m <- c(2.0863, 2.1340, 2.1008, 1.9565, 2.0413, NA, NA) f <- c(1.8938, 1.9709, 1.8613, 2.0836, 1.9485, 2.0630, 1.9143) In a R help message/reply from Sep 30, 2001, it was noted that the "power.t.test" function

Hello, I am trying to perform a two-factor ANOVA analysis using a blocking design with "Vol" as the response variable. My intent is to have "Rater" treated as the treatment variable and the "Pipe" treated as the blocking variable. I am reading and preparing my dataset using the following three lines of code: values <- read.table("filename",