R/puffin.R

In ipsRdbs: Introduction to Probability, Statistics and R for Data-Based Sciences

#' Puffin nesting data set. It contains data regarding 
#' nesting habits of common puffin
#' 
#' @source \insertCite{puffindata;textual}{ipsRdbs}. 
#' @format A data frame with 38 rows and 5 columns:
#' \describe{
#'   \item{Nesting_Frequency}{Number of nests}
#'   \item{Grass_Cover}{Percentage of area covered by grass}
#'   \item{Mean_Soil_Depth}{Mean soil depth in centimeter}
#'   \item{Slope_Angle}{Slope angle in degrees}
#'   \item{Distance_from_Edge}{Distance of the plot from the cliff edge in meter}
#' }
#' @references
#' \insertAllCited{}
#' @examples
#' head(puffin)
#' dim(puffin)
#' summary(puffin)
#' pairs(puffin)
#' puffin$sqrtfreq <- sqrt(puffin$Nesting_Frequency)
#' puff.sqlm <- lm(sqrtfreq~ Grass_Cover + Mean_Soil_Depth + Slope_Angle 
#' +Distance_from_Edge, data=puffin) 
#' old.par <- par(no.readonly = TRUE)
#' par(mfrow=c(2,1))
#' qqnorm(puff.sqlm$res,main="Normal probability plot", col=2)
#' qqline(puff.sqlm$res, col="blue")
#' plot(puff.sqlm$fit, puff.sqlm$res,xlab="Fitted values",ylab="Residuals", 
#' main="Anscombe plot")
#' abline(h=0)
#' summary(puff.sqlm)
#' par(old.par)
#' #####################################
#' # F test for two betas at the  same time: 
#' ######################################

#' puff.sqlm2 <- lm(sqrtfreq~ Mean_Soil_Depth + Distance_from_Edge, data=puffin) 
#' anova(puff.sqlm)
#' anova(puff.sqlm2)
#' fval <-  1/2*(14.245-12.756)/0.387 # 1.924 
#' qf(0.95, 2, 33) # 3.28
#' 1-pf(fval, 2, 33) # 0.162
#' anova(puff.sqlm2, puff.sqlm)

"puffin"