reno.components.Stock

class reno.components.Stock(label=None, init=None, doc=None, min=None, max=None, dim=1, group='', dtype=None)

Bases: TrackedReference

A stock represents some bucket or quantity of material/thing that can accumulate (in_flows) or deplete (out_flows) over time.

https://en.wikipedia.org/wiki/Stock_and_flow https://insightmaker.com/docs/stocks

Note that stock update equations are based on the previous timestep’s values for all references (as opposed to flows/vars), e.g.:

` stock(t) = stock(t-1) + in_flows(t-1) - out_flows(t-1) `

Methods

__init__([label, init, doc, min, max, dim, ...])
clip(min, max)
combine_eqs(eqs)	Helper function to convert a list of equations into a single combined equation.
compute_diff_eq()	Create a combined equation that accounts for both inflows and outflows.
debug_equation(t[, sample])
display()	Display a markdown with latex for inflow equations and outflow equations.
equal(obj)
equations(**kwargs)	Get a list of string latex representations for all in and out flows.
eval([t, save, compute_mask, force])	Compute the equation for the given timestep.
find_refs_of_type(search_type[, already_checked])	Actually recursive as opposed to seek_refs, returns a list of all equation parts matching passed type.
from_dict(data, refs)	Deserialize reference and parse data from dictionary previously saved from to_dict().
get_shape()	For now this is returning an integer because we only allow a single additional dimension.
get_type()	Similar to shape, this gets computed recursively, used to automatically determine if the value needs to be initialized with a certain numpy type.
history(index_eq)	Get a reference to a previous value of this reference.
initial_vals()	Subclasses that have a special way of defining the initial set of values (e.g. stocks with their _0 values) can override this function, automatically called at the end of populate().
is_static()	Convenience shortcut for reno.utils.is_static() - True if this equation doesn't rely on any dynamic values (thus constant), False if it does.
latex(**kwargs)	String representation suitable for a latex display.
max_refs()	Get any references found in the max constraint equation.
min_refs()	Get any references found in the min constraint equation.
not_equal(obj)
plot([ax, plot_kwargs])	Generate a matplotlib plot for this stock's simulation.
populate(n, steps)	Initialize the matrix of values with size n x steps.
pt(**refs)	Get a pytensor graph representing this piece of an equation.
pt_str(**refs)	Construct a string containing relevant pytensor code for this piece of the equation.
qual_name([dot])	Get a string with both the model and the reference name if this model is a submodel of something else.
resolve_init_array(obj_or_eq)	Convert a number or scalar/distribution into correct starting array.
seek_refs()	Immediate refs only, depth=1.
series_max()
series_min()
sum([axis])
to_dict()	Serialize class into a dictionary for saving to file.

Attributes

dtype	The type of each underlying value.
shape	The size of the data dimension, 1 by default.
timeseries	Get a timeseries view of the data (includes all historical data across all timesteps.)
model	Keep a reference to container model, makes it easier to compare refs across multiple models.
init	Initial value/equation for initial value for stock/flow/var at t=0
dim	Size of an optional extra dimension, allowing a given reference to describe a vector of values at every timestep.
implicit	Implicit components (normally created as subcomponents of more advanced operations) don't show up in diagrams, latex, or output JSON, since they are created by operations.
computed_mask	Follows same shape as value (up through first two dimensions), set of booleans indicating which values have already been evaluated and saved.
label	Label is what's used in any visual representation (e.g. allows spaces where name does not.).
doc	A docstring to explain/describe the reference.

Parameters:

• label (str)

• init (int | float | Distribution | Scalar | EquationPart)

• doc (str)

• min (EquationPart)

• max (EquationPart)

• dim (int)

• group (str)

• dtype (type)

__annotations__ = {}

__iadd__(obj)

__isub__(obj)

__module__ = 'reno.components'

__setattr__(name, value)

Implement setattr(self, name, value).

combine_eqs(eqs)

Helper function to convert a list of equations into a single combined equation. (Essentially a big summation operator.)

Parameters:

eqs (list[EquationPart])

Return type:

EquationPart

compute_diff_eq()

Create a combined equation that accounts for both inflows and outflows.

Return type:

EquationPart

debug_equation(t, sample=0, **kwargs)

display()

Display a markdown with latex for inflow equations and outflow equations.

equations(**kwargs)

Get a list of string latex representations for all in and out flows.

Return type:

list[str]

from_dict(data, refs)

Deserialize reference and parse data from dictionary previously saved from to_dict().

Parameters:

• data (dict)

• refs (dict[str, TrackedReference])

initial_vals()

Subclasses that have a special way of defining the initial set of values (e.g. stocks with their _0 values) can override this function, automatically called at the end of populate().

plot(ax=None, plot_kwargs=None)

Generate a matplotlib plot for this stock’s simulation.

to_dict()

Serialize class into a dictionary for saving to file. Stock has to modify the parent TrackedReference class serialization to account for equations being handled a little differently.

Return type:

dict