finam_vtk.PVDReader#

class finam_vtk.PVDReader(path, reference_date, time_unit, calendar='standard', outputs=None, grid_arguments=None)[source]#

Bases: TimeComponent

VTK reader component that steps along a date/time coordinate dimension of a dataset.

Parameters:

path (str) – Path to the PVD file to read.
reference_date (datetime.datetime) – Reference datetime to determine times.
time_unit (string) – Unit of the timesteps (e.g. “seconds”, “hours”, “days”, …)
calendar (str, optional) – Describes the calendar used in the time calculations. All the values currently defined in the CF metadata convention are supported. Valid calendars ‘standard’, ‘gregorian’, ‘proleptic_gregorian’ ‘noleap’, ‘365_day’, ‘360_day’, ‘julian’, ‘all_leap’, ‘366_day’ by default “standard”
outputs (list of str or DataArray, optional) – Output arrays to provide. By default all arrays found in the vtk file(s).
grid_arguments (dict, optional) – Arguments forwarded to grid_from_pyvista(), by default None

Attributes:

connector: The component’s tools.ConnectHelper.
inputs: dict: The component’s inputs.
logger: Logger for this component.
logger_name: Logger name derived from base logger name and class name.
metadata: The component’s metadata.
name: Component name.
next_time: The component’s predicted simulation time of the next pulls.
outputs: dict: The component’s outputs.
status: The component’s current status.
time: The component’s current simulation time.
uses_base_logger_name: Whether this class has a base_logger_name attribute.

Methods

`connect`(start_time)	Connect exchange data and metadata with linked components.
`create_connector`([pull_data, in_info_rules, ...])	Initialize the component's `tools.ConnectHelper`.
`finalize`()	Finalize and clean up the component.
`initialize`()	Initialize the component.
`try_connect`(start_time[, exchange_infos, ...])	Exchange the info and data with linked components.
`update`()	Update the component by one time step.
`validate`()	Validate the correctness of the component's settings and coupling.
`with_name`(name)	Renames the component and returns self.

connect(start_time)#

Connect exchange data and metadata with linked components.

The method can be called multiple times if there are failed pull attempts.

After each method call, the component should have status ComponentStatus.CONNECTED if connecting was completed, ComponentStatus.CONNECTING if some but not all required initial input(s) could be pulled, and ComponentStatus.CONNECTING_IDLE if nothing could be pulled.

Parameters:: start_time (datetime) – The composition’s starting time. Can be before the component’s actual time.

create_connector(pull_data=None, in_info_rules=None, out_info_rules=None, cache=True)#

Initialize the component’s tools.ConnectHelper.

See also try_connect(), connector and ConnectHelper for details.

Parameters:

pull_data (arraylike) – Names of the inputs that are to be pulled.
in_info_rules (dict) – Info transfer rules for inputs. See the examples for details.

See also tools.FromInput, tools.FromOutput and tools.FromValue.
out_info_rules (dict) – Info transfer rules for outputs. See the examples for details.

See also tools.FromInput, tools.FromOutput and tools.FromValue.
cache (bool) – Whether data and Info objects passed via try_connect() are cached for later calls. Default True.

Examples

The following examples show the usage of this method in _initialize().

Simple usage if no input data or any metadata from connected components is required:

self.inputs.add(name="In", time=self.time, grid=fm.NoGrid())
self.outputs.add(name="Out", time=self.time, grid=fm.NoGrid())
self.create_connector()

To pull specific inputs, use pull_data like this:

self.inputs.add(name="In1", time=self.time, grid=fm.NoGrid())
self.inputs.add(name="In2", time=self.time, grid=fm.NoGrid())

self.create_connector(pull_data=["In1", "In2"])

With the in_info_rules and out_info_rules, metadata can be transferred between coupling slots.

Here, the metadata for an output is taken from an input:

self.inputs.add(name="In", time=self.time, grid=None, units=None)
self.outputs.add(name="Out")

self.create_connector(
    out_info_rules={
        "Out": [
            fm.tools.FromInput("In")
        ]
    }
)

The Info object for output Out will be created and pushed automatically in try_connect() as soon as the metadata for In becomes available.

Here, the metadata of an output is composed from the metadata of two inputs and a user-defined value:

self.inputs.add(name="In1", time=self.time, grid=None, units=None)
self.inputs.add(name="In2", time=self.time, grid=None, units=None)
self.outputs.add(name="Out")

self.create_connector(
    out_info_rules={
        "Out": [
            fm.tools.FromInput("In1", ["time", "grid"]),
            fm.tools.FromInput("In2", ["units"]),
            fm.tools.FromValue("source", "FINAM"),
        ]
    }
)

The Info object for output Out would be automatically composed in try_connect() as soon as the infos of both inputs become available. time and grid would be taken from In1, units from In2, and source would be set to "finam".

Rules are evaluated in the given order. Later rules can overwrite attributes set by earlier rules.

finalize()#

Finalize and clean up the component.

After the method call, the component should have status ComponentStatus.FINALIZED.

initialize()#

Initialize the component.

After the method call, the component’s inputs and outputs must be available, and the component should have status ComponentStatus.INITIALIZED.

try_connect(start_time, exchange_infos=None, push_infos=None, push_data=None)#

Exchange the info and data with linked components.

Values passed by the arguments are cached internally for later calls to the method if the connector was created with cache=True (the default). Thus, it is sufficient to provide only data and infos that became newly available. Giving the same data or infos repeatedly overwrites the cache.

Sets the component’s status according to success of exchange.

See also create_connector(), connector and ConnectHelper for details.

Parameters:

start_time (datetime) – the composition’s starting time as passed to Component.try_connect()
exchange_infos (dict of [str, Info]) – currently or newly available input data infos by input name
push_infos (dict of [str, Info]) – currently or newly available output data infos by output name
push_data (dict of [str, array-like]) – currently or newly available output data by output name

update()#

Update the component by one time step. Push new values to outputs.

After the method call, the component should have status ComponentStatus.UPDATED or ComponentStatus.FINISHED.

validate()#

Validate the correctness of the component’s settings and coupling.

After the method call, the component should have status ComponentStatus.VALIDATED.

with_name(name)#: Renames the component and returns self.

property connector#

The component’s tools.ConnectHelper.

property inputs#

The component’s inputs.

Type:: dict

property logger#: Logger for this component.

property logger_name#: Logger name derived from base logger name and class name.

property metadata#

The component’s metadata. Will only be called after the connect phase from Composition.metadata.

Components can overwrite this property to add their own specific metadata:

import finam as fm

class MyComponent(fm.Component):

    @property
    def metadata(self):
        # Get the default metadata
        md = super().metadata

        # Add your own metadata
        md["my_field"] = "some value"

        # Return the dictionary
        return md

Returns:

A dict with the following default metadata:

name - the component’s name
class - the component’s class
inputs - dict of metadata for all inputs
outputs - dict of metadata for all outputs

Return type:

dict

property name#: Component name.

property next_time#

The component’s predicted simulation time of the next pulls.

Can be None if the component has no inputs.

property outputs#

The component’s outputs.

Type:: dict

property status#: The component’s current status.

property time#: The component’s current simulation time.

property uses_base_logger_name#: Whether this class has a base_logger_name attribute. True.