https://github.com/oceanmodeling/xarray-selafin
An xarray engine for opening Selafin files (TELEMAC)
https://github.com/oceanmodeling/xarray-selafin
telemac xarray xarray-extension
Last synced: 5 months ago
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An xarray engine for opening Selafin files (TELEMAC)
- Host: GitHub
- URL: https://github.com/oceanmodeling/xarray-selafin
- Owner: oceanmodeling
- License: gpl-3.0
- Created: 2024-02-17T19:33:20.000Z (over 2 years ago)
- Default Branch: main
- Last Pushed: 2025-10-20T09:02:29.000Z (8 months ago)
- Last Synced: 2025-10-23T11:37:41.681Z (8 months ago)
- Topics: telemac, xarray, xarray-extension
- Language: Python
- Homepage: https://pypi.org/project/xarray-selafin/
- Size: 4.8 MB
- Stars: 7
- Watchers: 7
- Forks: 3
- Open Issues: 10
-
Metadata Files:
- Readme: README.md
- License: LICENSE.txt
Awesome Lists containing this project
README
[](https://pypi.python.org/pypi/xarray-selafin/)
[](https://github.com/oceanmodeling/xarray-selafin/actions/workflows/run_tests.yml)
# xarray backend for Selafin formats
Supports lazy loading by default.
## Install
To have the backend working in xarray, you need to follow these steps:
```
pip install xarray-selafin
```
or, if you are using conda/mamba:
```
conda install -c conda-forge xarray_selafin
```
## Read Selafin
```python
import xarray as xr
with xr.open_dataset("tests/data/r3d_tidal_flats.slf", engine="selafin") as ds:
print(ds) # do something with `ds`...
# `ds.close()` not necessary
ds = xr.open_dataset("tests/data/r3d_tidal_flats.slf", lang="fr", engine="selafin") # if variables are in French
print(ds) # do something with `ds`...
ds.close() # avoid a ResourceWarning (unclosed file)
```
```
Size: 5MB
Dimensions: (time: 17, plan: 21, node: 648)
Coordinates:
x (node) float32 3kB ...
y (node) float32 3kB ...
* time (time) datetime64[ns] 136B 1900-01-01 ... 1900-01-02T20:26:40
Dimensions without coordinates: plan, node
Data variables:
Z (time, plan, node) float32 925kB ...
U (time, plan, node) float32 925kB ...
V (time, plan, node) float32 925kB ...
W (time, plan, node) float32 925kB ...
MUD (time, plan, node) float32 925kB ...
Attributes:
title: Sloped flume Rouse profile test
language: en
float_size: 4
endian: >
params: (1, 0, 0, 0, 0, 0, 21, 5544, 0, 1)
ipobo: [ 1 264 263 ... 5411 5412 5413]
ikle2: [[155 153 156]\n [310 307 305]\n [308 310 305]\n ...\n [537 ...
ikle3: [[ 155 153 156 803 801 804]\n [ 310 307 305 ...
variables: {'Z': ('ELEVATION Z', 'M'), 'U': ('VELOCITY U', 'M/S'), 'V':...
date_start: (1900, 1, 1, 0, 0, 0)
```
## Indexing
```python
ds_last = ds.isel(time=-1) # last frame
```
## Manipulate variables
```python
ds = ds.assign(UTIMES100=lambda x: x.U * 100) # Add a new variable
# ds.attrs["variables"]["UTIMES100"] = ("UTIMES100", "My/Unit") # To provide variable name and unit (optional)
ds.drop_vars(["W"]) # Remove variable `VELOCITY W`
```
## Extracting a specific layer from a 3D DataSet
```python
ds_bottom = ds.selafin.get_dataset_as_2d(plan=0) # bottom layer
```
## Write Selafin
```python
ds.selafin.write("output_file.slf")
```
## DataSet content
### Dimensions
In 2D:
1. time
2. node
in 3D:
1. time
2. plan
3. node
### Coordinates
| Coordinate | Description |
|------------|------------------------|
| x | East mesh coordinates |
| y | North mesh coordinates |
| time | Datetime serie |
### Attributes
All attributes are optional except `ikle2`:
| Attribute | Description | Default value |
|------------|-------------------------------------------------------------------------|--------------------------------|
| title | Serafin title | "Converted with array-serafin" |
| language | Language for variable detection | "en" |
| float_size | Float size | 4 (single precision) |
| endian | File endianness | ">" |
| params | Table of integer parameters | (can be rebuilt) |
| ikle2 | Connectivity table in 2D (1-indexed) | - |
| ikle3 | Connectivity table in 3D (1-indexed, only in 3D, optional) | (can be rebuilt from 2D) |
| variables | Dictionary with variable names and units (key is variable abbreviation) | - |
| date_start | Starting date with integers (year to seconds) | (from first time serie) |