[julia-users] Scalar and array version of a function

[Uwe Fechner]

Hello,

what is the best way to implement a scalar and a vectorized version of a 
function?

My code:

const Z_REF = 10.0    # reference height for wind profile law
const ALPHA = 0.23375 # exponent of the wind profile law for Cabauw

""" 
calcWindAtHeight(v_wind_gnd, z)

Calculate the average wind speed for the given ground wind speed 
`v_wind_gnd` at a given height `z`. 
The ground wind speed is measured at the height `Z_REF`, a constant, that 
must have been defined
before. The exponential wind profile law is used in combination with the 
exponent `ALPHA`, that must
have been defined before, too.
"""
function calcWindAtHeight(v_wind_gnd, z::AbstractFloat)
    v_wind_gnd * (z / Z_REF)^ALPHA
end

"""
calcWindAtHeight(v_wind_gnd, Z)

Calculate the average wind speed for the given ground wind speed 
`v_wind_gnd` at a given height `Z`. 
The ground wind speed is measured at the height `Z_REF`, a constant, that 
must have been defined
before. The exponential wind profile law is used in combination with the 
exponent `ALPHA`, that must
have been defined before, too. If `Z` is an array, the function will return 
an array.
"""
function calcWindAtHeight(v_wind_gnd, Z::AbstractArray)
    result = similar(Z)
    for i in eachindex(Z) 
        result[i] = calcWindAtHeight(v_wind_gnd, Z[i])
    end
    result
end

Is this good programming style? Could it be improved?

Regards:

Uwe Fechner