Il 29/10/2017 22:45, Hervé Pagès ha scritto: In particular, I'd like to read more about how to create a backend for DelayedArray. Is there any documentation available beyond the reference manual?
I'm guilty. I plan to remedy this ASAP. In the mean time I'll be glad to help. Note that other people are already working (or planning to work) on other backends: Backend for remote HDF5 data: https://github.com/vjcitn/RemoteArray See issues #1, #2, #3 for some discussion about this. Backend for GDS files: https://github.com/Bioconductor/VariantExperiment/issues/1 Thank you, Hervé. Maybe I could use some help than! Discussions in issue #2 seems useful for my case. I have a specific question: when I create a DelayedArray with my backend, it seems that subset_seed_as_array() is called, which is not really intuitive. Is this normal? What is this first call supposed to do? In my case it fails with dimensionality problems (the array is empty). I did look into HDF5Array code, but I'm not sure I understand what the following is doing: .subset_HDF5ArraySeed_as_array <- function(seed, index) { ans_dim <- DelayedArray:::get_Nindex_lengths(index, dim(seed)) if (any(ans_dim == 0L)) { ans <- seed@first_val[0] dim(ans) <- ans_dim } else { ans <- h5read2(seed@file, seed@name, index) } ans } In particular, I'm not sure how to interpret the index variable, which seems to be a list. Each element "i" is a vector of indices for the i-th dimension? And what does seed@first_val[0] do? And the first_val attribute in general. Thank you very much for your help, francesco [[alternative HTML version deleted]] _______________________________________________ Bioc-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/bioc-devel
