1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
|
% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/H5constants.R
\name{h5const}
\alias{h5const}
\title{All constants used in HDF5}
\description{
These are all constants used in HDF5. They are stored in an environment with locked bindings so that
they cannot be changed. An overview of all constants can be seen with \code{h5const$overview}, listing all of them.
Each constant can be accessed using \code{$} and the name of the constant. See the examples below.
}
\details{
There are also some flags that govern edge cases of conversion from HDF5 to R. This is related to how integers are being treated and
the issue of R not being able to natively represent 64bit integers and not at all being able to represent unsigned 64bit integers
(even using add-on packages).
The constants all start with the term \code{H5TOR}. There are currently possible values
\describe{
\item{H5TOR_CONV_NONE}{Doesn't do any conversion. Every integer datatype with more than 32 bit is returned as 64bit integers. For
unsigned 64bit integers, the conversion to signed 64bit integers is done by truncation}
\item{H5TOR_CONV_INT64_INT_NOLOSS}{Under this setting, whenever a 64 bit integer would be returned, it is checked if it would also
fit into a 32 bit integer without data loss and returned as such if possible}
\item{H5TOR_CONV_INT64_FLOAT_NOLOSS}{Under this setting, whenever a 64 bit integer would be returned, it is checked if it would also
fit into a 64 bit floating point value without data loss and returned as such if possible}
\item{H5TOR_CONV_INT64_NOLOSS}{Combines \code{H5TOR_CONV_INT64_INT_NOLOSS} and \code{H5TOR_CONV_INT64_FLOAT_NOLOSS} and is set
as the default in the \code{hdf5r.h5tor_default} option.}
\item{H5TOR_CONV_INT64_FLOAT_FORCE}{Under this setting, whenever a 64 bit integer would be returned, it is coerced to a double
even if this results in a loss of precision. If a loss of precision occurs, a warning is issued. Please note that this also overrides
the use of \code{H5TOR_CONV_UNIT64_NA}. As loss of precision is already accepted, UINT64-values that are larger than LLONG_MAX will be represented
as their next possible floating point value.}
\item{H5TOR_CONV_UINT64_NA}{When converting an unsigned 64bit integer, any values that don't fit into a signed 64bit integer are
set to NA. If this flag is not set, then the values will be truncated to \code{LLONG_MAX}, the largest 64bit signed integer.}
\item{H5TOR_CONV_DEFAULT}{Is both \code{H5TOR_CONV_INT64_INT} and \code{H5TOR_CONV_UNIT64_FLOAT}}
}
}
\examples{
h5const$overview
h5const$H5F_ACC_RDWR
h5const$H5F_ACC_DEFAULT
# Combining flags
bitwOr(h5const$H5TOR_CONV_UINT64_NA, h5const$H5TOR_CONV_INT64_INT_NOLOSS)
}
\author{
Holger Hoefling
}
|
