Calculate wind direction and speed from u and v components.

wind.dispeed is a simple calculation of the wind direction for given u and v. Notice that these should already be converted to natural directions along E/N axes. wind.uv is the inverse.

Usage

wind.dirspeed(u, v,fieldname=c("Wind direction","Wind speed"),rad=FALSE)
wind.uv(wspeed,wdir,fieldname=c("U","V"),rad=FALSE)

Arguments

u,v

u and v components of the model wind. These may be either vectors or geofield objects. They must be rotated to true N/E axis for the wind direction to be correct! u may also be a list with components (u,v), in which case v should be missing.

wspeed,wdir

Wind speed and direction direction (radians or degrees).

fieldname

A character string giving the names for the result. Only necessary if u and v are geofield objects.

rad

If TRUE, the wind direction is in radians. If FALSE, it is in (decimal) degrees.

Value

A list with elements wdir and wspeed.

Details

Wind direction is given in degrees by default. If the wind speed is lower than 10E-6, the result is set to NA.

See also

geowind