Data frame with components: ozone, radiation, temperature, and wind. Measurements of daily ozone con- centration (ppb), wind speed (mph), daily maximum tempera- ture (degrees F), and solar radiation (langleys) on 111 days from May to September 1973 in New York. This data frame is similar to air in S-PLUS (or library(data) in S), but has a different definition for ozone (air contains cube-roots of ozone).