Rarr supports both Zarr version 2 and Zarr version 3 but some version 3 features are still a work in progress. In particular, it is known that the sharding codec is not yet implemented.
Reading Zarr arrays is reasonably well supported. Writing is available, but is more limited. Both aspects are under active development.
| Store Type | Status (reading / writing) |
Notes |
|---|---|---|
FilesystemStore |
✔ / ✔ | |
S3Store |
✔ / ❌ |
Currently there is only support for reading and writing a subset of the possible datatypes that can be found in a Zarr array. In some instances there are also limitations on the datatypes natively supported by R, requiring conversion from the Zarr datatype. The table below summarises the current status of datatype support. It will be updated as progress is made.
| Zarr Data Type | Status (reading / writing) |
Notes |
|---|---|---|
boolean |
✔ / ✔ | (via {grumpy}) |
int8 |
✔ / ✔ | (via {grumpy}) |
uint8 |
✔ / ✔ | (via {grumpy}) |
int16 |
✔ / ✔ | (via {grumpy}) |
uint16 |
✔ / ✔ | (via {grumpy}) |
int32 |
✔ / ✔ | (via {grumpy}) |
uint32 |
✔ / ✔ | (via {grumpy}) |
int64 |
✔ / ✔ | (via {grumpy}) |
uint64 |
✔ / ✔ | (via {grumpy}) |
half / float16 |
✔ / ❌ | (via {grumpy}) |
single / float32 |
✔ / ✔ | (via {grumpy}) |
double / float64 |
✔ / ✔ | (via {grumpy}) |
complex |
❌ / ❌ | |
timedelta |
❌ / ❌ | |
datetime |
❌ / ❌ | |
V2 string |
✔ / ✔ | (via {grumpy}) |
V3 null_terminated_bytes |
✔ / ✔ | (via {grumpy}) |
V2 Unicode |
✔ / ✔ | (via {grumpy}) |
V3 fixed_length_utf32 |
✔ / ✔ | (via {grumpy}) |
void * |
❌ / ❌ | |
| V2 structured data types | ✔ / ❌ | (via {grumpy}) |
| V3 structured data types | ✔ / ❌ | This type is superseded by V3 struct data types.and the
specification says implementation MUST NOT implement writing. (via
{grumpy}) |
| V3 struct data types | ✔ / ❌ | (via {grumpy}) |
| Library | Status (reading / writing) |
Notes |
|---|---|---|
zlib / gzip |
✔ / ✔ | |
bzip2 |
✔ / ✔ | |
blosc |
✔ / ✔ | |
LZMA |
✔ / ✔ | |
LZ4 |
✔ / ✔ | |
Zstd |
✔ / ✔ |
Please open an issue if support for a required compression codec is missing.
| Codec | Status (reading / writing) |
Notes |
|---|---|---|
endian |
✔ / ❌ | (via {grumpy}) |
transpose |
✔ / ✔ | |
VLen-UTF8 |
✔ / ✔ * | Writing supported only via update_zarr_array() |
| Feature | Status (reading / writing) |
Notes |
|---|---|---|
dimension_names |
✔ / ✔ | Corresponds to names(dimnames(x)) in R |