converting wind direction from character into degrees
wdir <- data.frame(ddd = c("CAL", "N", "NNE", "NE", "ENE", "E", "ESE", "SE", "SSE",
"S", "SSW", "SW", "WSW", "W", "WNW", "NW", "NNW"),
dir = c(NA, 0:15 * 22.5), stringsAsFactors = FALSE)