[julia-users] Find the indice of the element with the nearest value of a float in an array

[Fred]

Hi,

I am looking for the most efficient (fastest) way to find the indice of the 
element with the nearest value of a float in an array.

x = [1:0.1:10]

julia> x
91-element Array{Float64,1}:
  1.0
  1.1
  1.2
  1.3
  1.4
  ⋮  
  9.4
  9.5
  9.6
  9.7
  9.8
  9.9
 10.0

It is very easy to find the indice of an exact value of x, for example 8.2

julia> find(x .== 8.2)
1-element Array{Int64,1}:
 73

But if I want the indice of the closest value of 8.22

julia> minimum(abs(x-8.22))
0.02000000000000135

julia> find(x .== minimum(abs(x-8.22)))
0-element Array{Int64,1}


Of course it is easy to do that with a loop but is it the fastest solution ?

min_i = 0
min_x = 1.0

 for i=[1:length(x)]
       e = abs(collect(x)[i] - 8.22)
       if e < min_x
           min_x = e
           min_i = i
       end
 end

println(min_x, " -> ", min_i)
0.02000000000000135 -> 73


Thanks for your comments !