Unlike Int, Float32/Float64 is not architecture-specific. Common misperception.
--Tim On Monday, January 04, 2016 02:17:14 PM Charles Novaes de Santana wrote: > Thanks a lot for your message, Tim. > > I was wondering that it could be because of the AbstractFloat too. It makes > sense. > > I am using AbstractFloat because I want to make it clear that the matrix > has Float elements, but I don't want to specify the architecture of the > machine of the user, because I had problems with users using 32bits > machines. > > I will definitely read the link you sent me. And I will let you know what I > decide to use in our code. Thanks for your suggestion too!! > > Best, > > Charles > > On 4 January 2016 at 14:03, Tim Holy <[email protected]> wrote: > > It has nothing to do with whether you're using a Matrix (which is just an > > Array{T,2}) or general Arrays. The question is, do you have to use > > AbstractFloat? > > > > julia> a = Float64[1,2,3] > > > > 3-element Array{Float64,1}: > > 1.0 > > 2.0 > > 3.0 > > > > julia> b = AbstractFloat[1,2,3] > > > > 3-element Array{AbstractFloat,1}: > > 1.0 > > 2.0 > > 3.0 > > > > julia> log(a.^2) > > > > 3-element Array{Float64,1}: > > 0.0 > > 1.38629 > > 2.19722 > > > > julia> log(b.^2) > > ERROR: MethodError: `log` has no method matching log(::Array{Any,1}) > > > > julia> typeof(a.^2) > > Array{Float64,1} > > > > julia> typeof(b.^2) > > Array{Any,1} > > > > julia> Base.return_types(*, (AbstractFloat, AbstractFloat)) > > > > 8-element Array{Any,1}: > > Float32 > > Float64 > > Float16 > > BigFloat > > BigFloat > > BigFloat > > Union{} > > Any > > > > You could do this: > > julia> b2 = AbstractFloat[v^2 for v in b] > > > > 3-element Array{AbstractFloat,1}: > > 1.0 > > 4.0 > > 9.0 > > > > julia> log(b2) > > > > 3-element Array{Any,1}: > > 0.0 > > 1.38629 > > 2.19722 > > > > But overall, I highly recommend reading the performance tips page and > > these > > two sections of the FAQ: > > http://docs.julialang.org/en/stable/manual/faq/#what-does-type-stable-mean > > > > http://docs.julialang.org/en/stable/manual/faq/#how-do-abstract-or-ambiguo > > us-fields-in-types-interact-with-the-compiler > > > > Best, > > --Tim > > > > On Monday, January 04, 2016 01:47:44 PM Charles Novaes de Santana wrote: > > > Hi people, > > > > > > I would like to work with matrices represented as Arrays of Arrays of > > > > > > AbstractFloats. Something like this: > > > F=Array{AbstractFloat}[];#initialize the matrix F as an Array of > > > > > > Arrays of Float > > > > > > for (i in 1:10) > > > > > > Fi = Array(AbstractFloat,0);#initialize the vector Fi as an > > > > > > Array of Float > > > > > > for (k in 1:5) > > > > > > push!(Fi,k^2+i^2) > > > > > > end#end-fork > > > push!(F,Fi); > > > > > > end#end-fori > > > > > > typeof(F) > > > Array{Array{AbstractFloat,N},1} > > > > > > But I am experiencing problems to work with rows/columns of such Arrays. > > > > I > > > > > would like to calculate the logarithm of the square of elements of those > > > > > > rows/columns like this: > > > f = F[1];#a vector of AbstractFloat > > > > > > typeof(f) > > > Array{AbstractFloat,1} > > > > > > typeof(f.^2) > > > Array{Any,1} > > > > > > log(f.^2) > > > ERROR: MethodError: `log` has no method matching > > > > log(::Array{Any,1}) > > > > > I understand this error only happens because I am working with Arrays of > > > Arrays of AbstractFloats. If I run a similar code using a Matrix instead > > > > of > > > > > Array I don't have such problems: > > > A = rand(10,5);#a matrix of floats (similar to an array of > > > arrays) > > > > > > typeof(A) > > > Array{Float64,2} > > > > > > a = A[1,:];#a vector of Float > > > > > > typeof(a) > > > Array{Float64,2} > > > > > > typeof(a.^2) > > > Array{Float64,2} > > > > > > log(a.^2) > > > > > > everything runs smoothly. > > > > > > My question: Am I doing something wrong in the way I am dealing with the > > > Array of Arrays of AbstractFloat? Should I convert it to a Matrix? Or > > > should I convert its elements to Array of Float instead of Array of Any? > > > Any other suggestion? > > > > > > Thanks for your attention and for any advice! > > > > > > Charles
