Use ZARR V2.0 data types to convert between R native types and raw data.
r_to_dtype(x, dtype, na_value = NA, ...)dtype_to_r(x, dtype, na_value = NA, ...)
In case of r_to_dtype() a vector of encoded raw data is returned.
In case of dtype_to_r() a vector of an R type (appropriate for the specified dtype)
is returned if possible.
Object to be converted
The data type used for encoding/decoding raw data. The dtype is
a code consisting of at least 3 characters. The first character indicates the
endianness of the data: '<'
(little-endian), '>' (big-endian), or '|' (endianness not relevant).
The second character represents the main data type ('b' boolean (logical),
'i' signed integer, 'u' unsigned integer, 'f' floating point number,
'c' complex number). 'M' is used for date-time objects and 'm' for delta
time (see difftime()).
The following characters are numerical indicating the byte size of the data type.
For example: dtype = "<f4" means a 32 bit floating point number; dtype = "|b1"
means an 8 bit logical value.
The main types 'M' and 'm' should always be ended with the time unit between
square brackets for storing the date time (difference). A valid code would be "<M8[h].
For more details about dtypes see
ZARR V2.0
or vignette("dtypes").
When storing raw data, you may want to reserve a value to
represent missing values. This is also what R does for NA values.
Other software may use different values to represent missing values. Also,
some data types have insufficient storage capacity to store R NA values.
Therefore, you can use this argument to indicate which value should represent
missing values. By default it uses R NA. When set to NULL, missing values
are just processed as is, without any further notice or warning.
For more details see vignette("dtypes").
Ignored
Pepijn de Vries
One of the applications of BLOSC compression is in ZARR, which is used to store
n-dimensional structured data. r_to_dtype() and dtype_to_r() are convenience functions
that allows you to convert most common data types to R native types.
R natively only supports logical() (actually stored as 32 bit integer in memory),
integer() (signed 32 bit integers), numeric() (64 bit floating points) and complex()
(real and imaginary component both represented by a 64 bit floating point). R also has some
more complex classes, but those are generally derivatives of the aforementioned types.
The functions documented here will attempt to convert raw data to R types (or vice versa). As not all 'dtypes' have an appropriate R type counterpart, some conversions will not be possible directly and will result in an error.
For more details see vignette("dtypes").
## Encode volcano data to 16 bit floating point values
volcano_encoded <-
r_to_dtype(volcano, dtype = "Run the code above in your browser using DataLab