Monthly ozone measurements over Central America.

Description

This data set is a subset of the data from the 2006 ASA Data expo challenge, https://community.amstat.org/jointscsg-section/dataexpo/dataexpo2006. The data are monthly ozone averages on a very coarse 24 by 24 grid covering Central America, from Jan 1995 to Dec 2000. The data is stored in a 3d area with the first two dimensions representing latitude and longitude, and the third representing time.

Usage

ozone

Format

A 24 x 24 x 72 numeric array

References

https://community.amstat.org/jointscsg-section/dataexpo/dataexpo2006

Examples

value <- ozone[1, 1, ]
time <- 1:72
month.abbr <- c("Jan", "Feb", "Mar", "Apr", "May",
 "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec")
month <- factor(rep(month.abbr, length = 72), levels = month.abbr)
year <- rep(1:6, each = 12)
deseasf <- function(value) lm(value ~ month - 1)

models <- alply(ozone, 1:2, deseasf)
coefs <- laply(models, coef)
dimnames(coefs)[[3]] <- month.abbr
names(dimnames(coefs))[3] <- "month"

deseas <- laply(models, resid)
dimnames(deseas)[[3]] <- 1:72
names(dimnames(deseas))[3] <- "time"

dim(coefs)
dim(deseas)