tutil.jl - Granular.jl - Julia package for granular dynamics simulation
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       ---
       tutil.jl (2112B)
       ---
            1 #!/usr/bin/env julia
            2 
            3 export randpower
            4 """
            5     randpower([nvals], [distribution_power], [min_val], [max_val])
            6 
            7 Returns one or more random numbers from a power-law probability distribution.
            8 
            9 # Arguments
           10 * `dims::Any`: the dimensions of random values (default = 1)
           11 * `distribution_power::Number`: the distribution power (default = 1.)
           12 * `min_val::Number`: the lower bound of the distribution range (default = 0.)
           13 * `max_val::Number`: the upper bound of the distribution range (default = 1.)
           14 """
           15 @inline function randpower(dims::Any = 1,
           16                            distribution_power::Number = 1.,
           17                            min_val::Number = 0.,
           18                            max_val::Number = 1.)
           19 
           20     val = ((max_val^(distribution_power + 1.) - 
           21             min_val^(distribution_power + 1.)) * rand(Float64, dims) .+ 
           22            min_val^(distribution_power + 1.)) .^ 
           23             (1. / (distribution_power + 1.))
           24 
           25     if dims == 1
           26         return val[1]
           27     else
           28         return val
           29     end
           30 end
           31 
           32 export harmonicMean
           33 """
           34     harmonicMean(a, b)
           35 
           36 Returns the harmonic mean of two numbers `a::Number` and `b::Number`.
           37 """
           38 function harmonicMean(a::Number, b::Number)::Number
           39     if a ≈ 0. && b ≈ 0
           40         return 0.
           41     else
           42         return 2. * a * b / (a + b)
           43     end
           44 end
           45 
           46 export vecTo3d
           47 """
           48     function vecTo3d(input, fill)
           49 
           50 Convert a scalar or 2d vector to 3d by filling the missing component with the
           51 value `fill`. The returned 3-component vector is a Vector (or 1d Array) of
           52 the same type as the input.
           53 
           54 # Arguments
           55 * `input`: a scalar or two-component vector.
           56 * `fill::Real`: value to use for third
           57 """
           58 function vecTo3d(input::Any; fill::Real = 0.0)
           59     if length(input) > 3
           60         error("vecTo3d requires a scalar or input vector to of length 3 or " *
           61               "less, but input is $input")
           62     elseif length(input) == 3
           63         return input
           64     elseif length(input) == 2
           65         return [input[1], input[2], typeof(input[1])(fill)]
           66     elseif length(input) == 1
           67         return [input[1], typeof(input[1])(fill), typeof(input[1])(fill)]
           68     else
           69         error("input not understood: $input")
           70     end
           71 end
           72