[MDAL-Developer] Python-Bindings

[Peter Petrik]

Hi Paul,

great progress! Dataset is indeed only identified by time (MDAL_D_time)
function and is used on temporal data.

Feel free to create PR on MDAL to add your repository/package to the README
and also to the mdal.xyz docs.

Peter

On Sat, May 29, 2021 at 2:54 PM Paul Harwood <runette at gmail.com> wrote:

> I have one generic question - since I am looking at the best way to
> generalise Datasets.
>
> One Dataset Group can have multiple Datasets. Is there any occasion other
> than temporal data when this happens?
>
> If there is, what is the way to identify the meaning of the datasets. With
> temporal data, the different datasets can be identified using the
> MDAL_D_time function, but are there other equivalents?
>
> On Sat, 29 May 2021 at 13:50, Paul Harwood <runette at gmail.com> wrote:
>
>> the results from the previous code looks like
>>
>> """
>>
>> MDAL Version:  0.8.0
>>
>> MDAL Driver Count :16
>>
>> 0
>>
>> 2DM Mesh File
>>
>> XMS Tin Mesh File
>>
>> Selafin File
>>
>> Esri TIN
>>
>> Stanford PLY Ascii Mesh File
>>
>> Flo2D
>>
>> HEC-RAS 2D
>>
>> TUFLOW FV
>>
>> AnuGA
>>
>> UGRID Results
>>
>> GDAL NetCDF
>>
>> GDAL Grib
>>
>> DAT
>>
>> Binary DAT
>>
>> TUFLOW XMDF
>>
>> XDMF
>>
>> ['PLY:"data/ply/test_mesh.ply"']
>>
>> Driver : PLY
>>
>> Vertex Count : 38487
>>
>> Face Count : 76294
>>
>> Largest Face: 3
>>
>> Edge Count : 0
>>
>> CRS :
>>
>> Mesh extent : (413630.0, 416783.0, 379766.0, 382410.0)
>>
>> DatasetGroup Count : 4
>>
>>
>> Driver : PLY
>>
>> Vertex Count : 38487
>>
>> Face Count : 76294
>>
>> Largest Face: 3
>>
>> Edge Count : 0
>>
>> CRS :
>>
>> Mesh extent : (413630.0, 416783.0, 379766.0, 382410.0)
>>
>> Vertex Array Shape : (38487,)
>>
>> Face Array Shape : (76294,)
>>
>> Edges Array Shape : (0,)
>>
>>
>> DatasetGroup Name : Bed Elevation
>>
>> DatasetGroup Location : 1
>>
>> Dataset Count : 1
>>
>> Group has scalar values : True
>>
>> Group has temporal values : False
>>
>> Reference Time :
>>
>> Maximum Vertical Level Count : 0
>>
>> Minimum / Maximum ; (178.64, 465.043)
>>
>> Metadata : {'Bed Elevation': b'Bed Elevation'}
>>
>>
>> Dataset Shape : (38487,)
>> """
>>
>> On Sat, 29 May 2021 at 13:46, Paul Harwood <runette at gmail.com> wrote:
>>
>>> As promised - I have been working on some Python Bindings. I now have a
>>> 0.9.0b1 type release :
>>>
>>> See https://github.com/ViRGIS-Team/mdal-python
>>>
>>> There is a conda install for this in the process of being created.
>>>
>>> There is some documentation in the process of being created.
>>>
>>> Currently, this integration can:
>>>
>>> - read all MDAL compatible file formats,
>>> - access the metadata for the source,
>>> - access the vertex, face and edge data as NumPy arrays,
>>> - access 'double' datasets (both scalar and vector) as NumPy arrays, and
>>> - convert the MDAL source mesh into a meshio mesh object (with some
>>> restrictions currently).
>>> - This version does not currently allow the MDAL source mesh to be
>>> written or amended.
>>>
>>> Note this very much beta and has not been comprehensively tested. The
>>> following script has been run successfully on a number of different test
>>> files and shows the usage.
>>>
>>> All comments and improvements welcome.
>>>
>>> """
>>>
>>> import mdalfrom mdal import Datasource
>>> print(f"MDAL Version:  {mdal.getVersionString()}")print(f"MDAL Driver Count :{mdal.getDriverCount()}")print(mdal.getLastStatus())
>>> for driver in mdal.getDrivers():
>>>     print(driver.long_name)
>>>
>>> ds = Datasource("data/ply/test_mesh.ply")print(ds.meshes)
>>> mesh = ds.load(0)print(f"Driver : {mesh.driverName}")print(f"Vertex Count : {mesh.vertexCount}")print(f"Face Count : {mesh.faceCount}")print(f"Largest Face: {mesh.largestFace}")print(f"Edge Count : {mesh.edgeCount}")print(f"CRS : {mesh.projection}")print(f"Mesh extent : {mesh.extent}")print(f"DatasetGroup Count : {mesh.groupCount}")print("")
>>> mesh = ds.load(ds.meshes[0])print(f"Driver : {mesh.driverName}")print(f"Vertex Count : {mesh.vertexCount}")print(f"Face Count : {mesh.faceCount}")print(f"Largest Face: {mesh.largestFace}")print(f"Edge Count : {mesh.edgeCount}")print(f"CRS : {mesh.projection}")print(f"Mesh extent : {mesh.extent}")
>>> vertex = mesh.getVertices()print(f"Vertex Array Shape : {vertex.shape}")
>>> faces = mesh.getFaces()print(f"Face Array Shape : {faces.shape}")
>>> edges = mesh.getEdges()print(f"Edges Array Shape : {edges.shape}")
>>> print("")
>>> group = mesh.getGroup(0)print(f"DatasetGroup Name : {group.name}")print(f"DatasetGroup Location : {group.location}")print(f"Dataset Count : {group.datasetCount}")print(f"Group has scalar values : {group.hasScalar}")print(f"Group has temporal values : {group.isTemporal}")print(f"Reference Time : {group.referenceTime}")print(f"Maximum Vertical Level Count : {group.levelCount}")print(f"Minimum / Maximum ; {group.minmax}")print(f"Metadata : {group.getMetadata()}")
>>> print("")
>>> data = group.getDataAsDouble(0)print(f"Dataset Shape : {data.shape}")
>>>
>>> """
>>> (see next email to see results from this code)
>>>
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