A simple, fast file format for storing numeric arrays. I built this package because I was frustrated with the speed and complexity of other formats.

The basic format (raw) saves bit arrays as flat files with a minimal header. Arrays can be read back and will be formatted into the correct Type and size.

Save an Array to a file:

saveraw{T<:Number,V}(a::AbstractArray{T,V},fname::String)

Append a Number or Array to an existing file. If appending an Array, appends along last dimension. This function requires that the two Arrays have the same size (except the last dimension) and Type.

appendraw{T<:Number,V}(a::AbstractArray{T,V},fname::String)
appendraw(a::T,fname::String) where {T<:Number} = appendraw([a],fname)

The saveraw and readraw functions can also be used on IO objects if you want to pull the data stream from something other than a file. For example:

julia> using GZip,RawFile

julia> GZip.open("test.raw.gz","w") do f
           saveraw(rand(100,10,50),f)
       end

julia> GZip.open("test.raw.gz") do f
           rawsize(f)
       end
(100, 10, 50)

Read an Array from a file:

readraw(fname::String)

Just read the Array size from the header and return a Tuple

rawsize(fname::String)

These functions were made if you are handling large files and want to be able to write them progressively without keeping all of the data in memory at one time.

To save an Array progressively, each piece needs to have the same dimensions (except for the last, where they will be concatenated)

saveraw(func::Function,fname::String)

julia> saveraw("test.raw") do f
           for i=1:10
               write(f,rand(100,10,5))
           end
       end
julia> rawsize("test.raw")
(100, 10, 50)

The RawFileIter Type is an interator that can be used to read through a file returning chunks of data (based on the parameter num_batch), instead of the entire file at once. The iteration is also encapsulated into the readraw function for convenience.

RawFileIter(fname::String,num_batch::Int)
readraw(func::Function,fname::String,batch::Int)

julia> for d in RawFileIter("test.raw",20)
                  @info(size(d))
              end
[ Info: (100, 10, 20)
[ Info: (100, 10, 20)
[ Info: (100, 10, 10)

julia> readraw("test.raw",20) do c
           @info(size(c))
       end
[ Info: (100, 10, 20)
[ Info: (100, 10, 20)
[ Info: (100, 10, 10)