conv_v001¶

Nearest-neighbour interpolation.

Version 1 of HydPy-C performs simple nearest-neighbour interpolations between an arbitrary number of models (or data files) providing output and an arbitrary number of models requiring input.

Integration tests¶

Note

When new to HydPy, consider reading section How to understand integration tests? first.

We perform the following examples over a simulation period of 3 days:

>>> from hydpy import pub, Nodes, Element
>>> pub.timegrids = "2000-01-01", "2000-01-04", "1d"

conv_v001 implements no parameter with values depending on the simulation step size, which is why we can pass anything (or nothing) to function parameterstep() without changing the following results:

>>> from hydpy.models.conv_v001 import *
>>> parameterstep()

Due to the following configuration, conv_v001 queries its input from the inlet nodes in1 and in2 and passes the interpolation results to the outlet nodes out1, out2, out3, and out4:

>>> from hydpy import *
>>> in1, in2 = Node("in1"), Node("in2")
>>> element = Element("conv",
...                   inlets=(in1, in2),
...                   outlets=["out1", "out2", "out3", "out4"])

The following coordinate definitions contain the particular case of outlet node out4, being in the middle of inlet nodes in1 and in2 exactly:

>>> inputcoordinates(
...     in1=(0.0, 3.0),
...     in2=(2.0, -1.0))
>>> outputcoordinates(
...     out1=(0.0, 3.0),
...     out2=(3.0, -2.0),
...     out3=(1.0, 2.0),
...     out4=(1.0, 1.0))

In the first example, we perform a strict nearest-neighbour interpolation, where we always take only one input location into account, even in case of missing data:

>>> maxnmbinputs(1)

conv_v001 does not implement any state or log sequences and thus has no memory at all, making finalising the test setup quite easy. We only need to define time-series for both inlet nodes. Note that we set some numpy nan values to demonstrate how conv_v001 deals with missing values:

>>> element.model = model
>>> from hydpy.core.testtools import IntegrationTest
>>> test = IntegrationTest(element)
>>> test.dateformat = "%Y-%m-%d"
>>> with pub.options.checkseries(False):
...     in1.sequences.sim.series = 1.0, 2.0, nan
...     in2.sequences.sim.series = 4.0, nan, nan

The calculated results provide no supprises. However, outlet node out4 receives the output of node in1 instead of the equidistant node in2, which is due to their definition order when preparing parameter InputCoordinates above:

>>> test()
|       date |      inputs |                outputs | in1 | in2 | out1 | out2 | out3 | out4 |
---------------------------------------------------------------------------------------------
| 2000-01-01 | 1.0     4.0 | 1.0  4.0  1.0      1.0 | 1.0 | 4.0 |  1.0 |  4.0 |  1.0 |  1.0 |
| 2000-01-02 | 2.0     nan | 2.0  nan  2.0      2.0 | 2.0 | nan |  2.0 |  nan |  2.0 |  2.0 |
| 2000-01-03 | nan     nan | nan  nan  nan      nan | nan | nan |  nan |  nan |  nan |  nan |

For the last timestep, where no input values are available at all, there is nothing we can do. However, by using the second nearest location as an alternative, we at least achieve complete output for the second timestep:

>>> maxnmbinputs(2)
>>> test()
|       date |      inputs |                outputs | in1 | in2 | out1 | out2 | out3 | out4 |
---------------------------------------------------------------------------------------------
| 2000-01-01 | 1.0     4.0 | 1.0  4.0  1.0      1.0 | 1.0 | 4.0 |  1.0 |  4.0 |  1.0 |  1.0 |
| 2000-01-02 | 2.0     nan | 2.0  2.0  2.0      2.0 | 2.0 | nan |  2.0 |  2.0 |  2.0 |  2.0 |
| 2000-01-03 | nan     nan | nan  nan  nan      nan | nan | nan |  nan |  nan |  nan |  nan |

class hydpy.models.conv_v001.Model[source]¶

Bases: hydpy.models.conv.conv_model.Model

Version 1 of the Conv model.

The following “inlet update methods” are called in the given sequence at the beginning of each simulation step:

Pick_Inputs_V1 Pick the input from all inlet nodes.

The following “run methods” are called in the given sequence during each simulation step:

Calc_Outputs_V1 Perform a simple proximity-based interpolation.

The following “outlet update methods” are called in the given sequence at the end of each simulation step:

Pass_Outputs_V1 Pass the output to all outlet nodes.

class hydpy.models.conv_v001.ControlParameters(master: hydpy.core.parametertools.Parameters, cls_fastaccess: Optional[Type[hydpy.core.parametertools.FastAccessParameter]] = None, cymodel: Optional[hydpy.core.typingtools.CyModelProtocol] = None)¶

Bases: hydpy.core.variabletools.SubVariables[hydpy.core.parametertools.Parameters, Parameter, hydpy.core.parametertools.FastAccessParameter]

Control parameters of model conv_v001.