local variable T conflicts with a static parameter warining - class

Question

I'm getting warning that I don't understand.
I first run the following code:
type PDF{T <: Real}
𝛑::Vector{Float64} # K
μs::Matrix{T} # D x K
Σs::Vector{Matrix{T}} # K{D x D}
end
type Q{T <: Real}
w::Union{Float64, Vector{Float64}}
μpair::Union{Vector{T}, Matrix{T}}
Σpair::Union{Matrix{T}, Tuple{Matrix{T}, Matrix{T}} } # K{D x D}
end
type Smod{T <: Real}
H::Matrix{T} # D x D
Σs::Vector{Matrix{T}} # K{D x D}
qs::Vector{Q{T}}
end
type Scale{T <: Real}
μ::Vector{T} # D
Σ::Matrix{T} # D x D
end
type Parameters{T <: Real}
scale::Scale{T}
w::Vector{Float64}
maxNumCompsBeforeCompression::Integer
numComponentsAbsorbed::Integer
end
type KDE{T}
pdf::PDF{T}
smod::Smod{T}
params::Parameters{T}
end
And when after this I run the following snippet in IJulia
function initializeKDE{T <: Real}(x::Vector{T})
d = size(x,1)
T = typeof(x)
𝛑 = ones(Float64, 1)
μs = Array(T, d,1)
μs[:,1] = x
Σs = Array(Matrix{T}, 0)
pdf = PDF(𝛑, μs, Σs)
H = zeros(T, d,d)
qs = Array(Q{T}, 0)
smod = Smod(H, Σs, qs)
scale = Scale(x, H)
w = [0.0, 1.0]
maxNumCompsBeforeCompression = min(10, (0.5d^2 + d))
numComponentsAbsorbed = 0
params = Params(scale, w, maxNumCompsBeforeCompression, numComponentsAbsorbed)
kde = KDE(pdf, smod, params)
return kde::KDE
end
I get the following warning:
WARNING: local variable T conflicts with a static parameter in initializeKDE at In[4]:3.
where In[4]:3 corresponds to the 3rd line of the 2nd snippet.
Can anyone explain in human english what this warning is saying?

Answer 1

This is saying that you are trying to use T in two different ways: once as a "static parameter" and once as a local variable.
Firstly, you are using T as the parameter with which you are parametrising the function initializeKDE:
function initializeKDE{T <: Real}(x::Vector{T})
But then you are trying to redefine a new T in that third line:
T = typeof(x)
What are you trying to do here? If you are trying to define T to be the type of the elements that the vector x contains, then you should just delete this line and everything should just work -- T will automatically take the element type (eltype) of the vector that you pass to the initializeKDE function.