def extrapolate_error(self):
"""Estimate the numerical error to be expected when applying all
methods available based on the results of the current and the
last method.
Note that this expolation strategy cannot be applied on the first
method. If the current method is the first one, `-999.9` is returned.
>>> from hydpy.models.test_v1 import *
>>> parameterstep()
>>> model.numvars.error = 1e-2
>>> model.numvars.last_error = 1e-1
>>> model.numvars.idx_method = 10
>>> model.extrapolate_error()
>>> from hydpy import round_
>>> round_(model.numvars.extrapolated_error)
0.01
>>> model.numvars.idx_method = 9
>>> model.extrapolate_error()
>>> round_(model.numvars.extrapolated_error)
0.001
"""
if self.numvars.idx_method > 2:
self.numvars.extrapolated_error = modelutils.exp(
modelutils.log(self.numvars.error) +
(modelutils.log(self.numvars.error) -
modelutils.log(self.numvars.last_error)) *
(self.numconsts.nmb_methods - self.numvars.idx_method))
else:
self.numvars.extrapolated_error = -999.9
def __call__(model: modeltools.Model) -> None:
flu = model.sequences.fluxes.fastaccess
old = model.sequences.states.fastaccess_old
new = model.sequences.states.fastaccess_new
if flu.rk <= 0.:
new.qa = new.qz
elif flu.rk > 1e200:
new.qa = old.qa+new.qz-old.qz
else:
d_temp = (1.-modelutils.exp(-1./flu.rk))
new.qa = (old.qa +
(old.qz-old.qa)*d_temp +
(new.qz-old.qz)*(1.-flu.rk*d_temp))
def __call__(model: modeltools.Model) -> None:
inp = model.sequences.inputs.fastaccess
flu = model.sequences.fluxes.fastaccess
flu.saturationvapourpressure = 0.6108 * modelutils.exp(
17.27 * inp.airtemperature / (inp.airtemperature + 237.3))
def calc_qa_v1(self):
"""Calculate outflow.
The working equation is the analytical solution of the linear storage
equation under the assumption of constant change in inflow during
the simulation time step.
Required flux sequence:
|RK|
Required state sequence:
|QZ|
Updated state sequence:
|QA|
Basic equation:
:math:`QA_{neu} = QA_{alt} +
(QZ_{alt}-QA_{alt}) \\cdot (1-exp(-RK^{-1})) +
(QZ_{neu}-QZ_{alt}) \\cdot (1-RK\\cdot(1-exp(-RK^{-1})))`
Examples:
A normal test case:
>>> from hydpy.models.lstream import *
>>> parameterstep()
>>> fluxes.rk(0.1)
>>> states.qz.old = 2.0
>>> states.qz.new = 4.0
>>> states.qa.old = 3.0
>>> model.calc_qa_v1()
>>> states.qa
qa(3.800054)
First extreme test case (zero division is circumvented):
>>> fluxes.rk(0.0)
>>> model.calc_qa_v1()
>>> states.qa
qa(4.0)
Second extreme test case (numerical overflow is circumvented):
>>> fluxes.rk(1e201)
>>> model.calc_qa_v1()
>>> states.qa
qa(5.0)
"""
flu = self.sequences.fluxes.fastaccess
old = self.sequences.states.fastaccess_old
new = self.sequences.states.fastaccess_new
aid = self.sequences.aides.fastaccess
if flu.rk <= 0.:
new.qa = new.qz
elif flu.rk > 1e200:
new.qa = old.qa + new.qz - old.qz
else:
aid.temp = (1. - modelutils.exp(-1. / flu.rk))
new.qa = (old.qa + (old.qz - old.qa) * aid.temp + (new.qz - old.qz) *
(1. - flu.rk * aid.temp))
