H5Sselect_hyperslab: Perform operation between an existing selection and an...

In grimbough/rhdf5: R Interface to HDF5

Perform operation between an existing selection and an another hyperslab definition.

Description

Combines a hyperslab selection specified by start, stride, count and block arguments with the current selection for the dataspace represented by h5space.

Usage

H5Sselect_hyperslab(
  h5space,
  op = h5default("H5S_SELECT"),
  start = NULL,
  stride = NULL,
  count = NULL,
  block = NULL
)

Arguments

h5space	H5IdComponent object representing a dataspace.
op	Character string defined the operation used to join the two dataspaces. See h5const("H5S_SELECT") for the list of available options.
start, stride, count, block	Integer vectors, each with length equal to the rank of the dataspace. These parameters define the new hyperslab to select.

Details

H5Sselect_hyperslab is similar to, but subtly different from, H5Scombine_hyperslab(). The former modifies the selection of the dataspace provided in the h5space argument, while the later returns a new dataspace with the combined selection.

Examples

## create a 1 dimensional dataspace
sid_1 <- H5Screate_simple(dims = 20)

## select a single block of 5 points in sid_1
## this is equivalent to [11:16] in R syntax
H5Sselect_hyperslab(sid_1, start = 11, stride = 1, 
                    block = 5, count = 1)
                    
## confirm we have selected 5 in our original dataspace
H5Sget_select_npoints(sid_1)

## combine the existing selection with a new
## selection consisting of 2 blocks each of 1 point
## equivalent to [c(3,5)] in R syntax
H5Sselect_hyperslab(sid_1, op = "H5S_SELECT_OR",
                     start = 3, stride = 2, 
                     block = 1, count = 2)

## The dataspace now has 7 points selected
H5Sget_select_npoints(sid_1)

## tidy up
H5Sclose(sid_1)

grimbough/rhdf5 documentation built on Sept. 14, 2024, 8:41 a.m.