hbranch_v1¶

Version 1 of the HydPy-H-Branch model allows for branching the summed input from some inlet nodes to an arbitrary number of outlet nodes. In the original HBV96 implementation, it is supposed to separate inflowing discharge, but in HydPy it can be used for arbitrary variables. Calculations are performed for each branch individually by linear interpolation (or extrapolation) following tabulated supporting points.

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 10 hours:
>>> from hydpy import pub, Nodes, Element
>>> pub.timegrids = "01.01.2000 00:00", "01.01.2000 10:00", "1h"
hbranch_v1 has 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.hbranch_v1 import *
>>> parameterstep()
The hbranch_v1 model queries its inflow from two inlet Node objects and passes the branched outflow to three outlet Node objects. In contrast to most other application models, we need to define the parameter values before connecting the model to its Element object, called branch:
>>> nodes = Nodes("input1", "input2", "output1", "output2", "output3")
>>> branch = Element("branch",
...                  inlets=["input1", "input2"],
...                  outlets=["output1", "output2", "output3"])
>>> xpoints(0.0, 2.0, 4.0, 6.0)
>>> ypoints(output1=[0.0, 1.0, 2.0, 3.0],
...         output2=[0.0, 1.0, 0.0, 0.0],
...         output3=[0.0, 0.0, 2.0, 6.0])
>>> branch.model = model
We do not have to define any initial values in the test settings, due to application model hbranch_v1 having no memory at all:
>>> from hydpy.core.testtools import IntegrationTest
>>> test = IntegrationTest(branch)
>>> test.dateformat = "%H:%M"
The (identical) values of the inlet nodes input1 and input2 define no realistic inflow series. Instead, they are just intended to show the behaviour of hbranch_v1 within and slightly outside the current range defined by parameter XPoints:
>>> import numpy
>>> nodes.input1.sequences.sim.series = numpy.arange(-1, 9)/2
>>> nodes.input2.sequences.sim.series = numpy.arange(-1, 9)/2
The results for outlet node output1 clearly show that the linear interpolation is extrapolated both below and above the current range of parameter XPoints. The values of node output2 point out that inverse relationships are allowed. The values of node output3 raise to fast for high input values, showing that hbranch_v1 does not care for equality between the total sum of input and output values:
>>> test("hbranch_v1_ex1")
|  date | input |             outputs | input1 | input2 | output1 | output2 | output3 |
---------------------------------------------------------------------------------------
| 00:00 |  -1.0 | -0.5  -0.5      0.0 |   -0.5 |   -0.5 |    -0.5 |    -0.5 |     0.0 |
| 01:00 |   0.0 |  0.0   0.0      0.0 |    0.0 |    0.0 |     0.0 |     0.0 |     0.0 |
| 02:00 |   1.0 |  0.5   0.5      0.0 |    0.5 |    0.5 |     0.5 |     0.5 |     0.0 |
| 03:00 |   2.0 |  1.0   1.0      0.0 |    1.0 |    1.0 |     1.0 |     1.0 |     0.0 |
| 04:00 |   3.0 |  1.5   0.5      1.0 |    1.5 |    1.5 |     1.5 |     0.5 |     1.0 |
| 05:00 |   4.0 |  2.0   0.0      2.0 |    2.0 |    2.0 |     2.0 |     0.0 |     2.0 |
| 06:00 |   5.0 |  2.5   0.0      4.0 |    2.5 |    2.5 |     2.5 |     0.0 |     4.0 |
| 07:00 |   6.0 |  3.0   0.0      6.0 |    3.0 |    3.0 |     3.0 |     0.0 |     6.0 |
| 08:00 |   7.0 |  3.5   0.0      8.0 |    3.5 |    3.5 |     3.5 |     0.0 |     8.0 |
| 09:00 |   8.0 |  4.0   0.0     10.0 |    4.0 |    4.0 |     4.0 |     0.0 |    10.0 |
Click here to see the graph

class hydpy.models.hbranch_v1.Model[source]¶

Bases: hydpy.models.hbranch.hbranch_model.Model

The HBV96 version of HydPy-H-Stream (hbranch_v1).

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

Pick_Input_V1 Updates Input based on Total.

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

Calc_Outputs_V1 Performs the actual interpolation or extrapolation.

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

Pass_Outputs_V1 Updates Branched based on Outputs.

class hydpy.models.hbranch_v1.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 hbranch_v1.