Incrementally growing datafield with JLD

Let’s say I have a matrix stored in a file and I want to add columns over time. I want to add them in chunks so that I do not open/close the file all the time and I also want compression.

HDF5 allows me to do so for basic types (i.e. eltype Float64) with an initial d_create and set_dims! magic afterwards (see doc and search for set_dims!). Of course, I can do exactly the same for JLD files, because they are basically HDF5.

Excerpt from HDF5.jl doc:

b = d_create(fid, "b", Int, ((1000,),(-1,)), "chunk", (100,)) #-1 is equivalent to typemax(Hsize)
set_dims!(b, (10000,))
b[1:10000] = collect(1:10000)

However, let’s say the matrix has eltype Complex128. Plain HDF5 doesn’t know complex numbers. This is where JLD is convenient. But I can’t apply the d_create/set_dims! strategy here because those functions are inherited from HDF5.jl and don’t allow for datatype Complex128.

Is there a way to get this (incrementally growing datafield) done nicely with JLD?