Introduction

OVDS-Utils is a python library implementing classes and wrapers with easier to comprehend interfaces to openvds.

Examples are:

• VDS class implementing __getitem__ method for easy data read out and many others feature to make life easier.

To install:

Run pip install ovds-utils or execute python setup.py install in the source directory

Creating and reading VDS source example

You can easily create and access the VDS source/file by simply creating a VDS class instance and using __getitem__ method to read data.

import numpy as np

from ovds_utils.ovds.enums import BrickSizes
from ovds_utils.vds import VDS

shape = (251, 51, 126)
data = np.random.rand(*shape).astype(np.float32)

vds = VDS(
    path="example.vds",
    connection_string="",
    shape=shape,
    data=data,
    databrick_size=BrickSizes.BrickSize_128,
    access_mode=AccessModes.Create,
)

print(vds[:10,0,0])
>>> [0.14836921 0.06490713 0.05770212 0.2364456  0.49000826 0.1573576
 0.5017615  0.456749   0.6573513  0.72831243]

Writing to VDS source chunk by chunk

import numpy as np

from ovds_utils.metadata import MetadataTypes, MetadataValue
from ovds_utils.ovds.enums import BrickSizes, Formats
from ovds_utils.vds import VDS, Channel, Components, Formats, AccessModes

metadata = {
    "example": MetadataValue(value="value", category="category#1", type=MetadataTypes.String)
}

shape = (251, 51, 126)
data = np.random.rand(*shape).astype(np.float64)
zeros = np.zeros(shape, dtype=np.float64)

vds = VDS(
    "example.vds",
    data=zeros,
    metadata_dict=metadata,
    databrick_size=BrickSizes.BrickSize_64,
    access_mode=AccessModes.Create,
    channels=[
        Channel(
            name="Channel0",
            format=Formats.R64,
            unit="unitless",
            value_range_min=0.0,
            value_range_max=1000.0,
            components=Components.Components_1
        )
    ]
)
for c in vds.channel(0).chunks():
    c[:, :, :] = data[c.slices]
    c.release()
vds.channel(0).commit()

print(vds[:10,0,0])
>>> [0.14836921 0.06490713 0.05770212 0.2364456  0.49000826 0.1573576
 0.5017615  0.456749   0.6573513  0.72831243]

Links

• https://pypi.org/project/ovds-utils/