Package 'godley'

Add equations to the model

Description

Add equations to the model

Usage

add_equation(model, ...)

Arguments

model	SFC model object
...	additional arguments passed to the function.

Value

updated SFC model object containing added equation

---

Add single equation to the model

Description

helper for add_equation()

Usage

add_equation_single(model, equation, hidden = FALSE, desc = "")

Arguments

model	SFC model object
equation	string equation in format: 'x = y + z - a * b + (c + d) / e + f[-1]'
hidden	logical, indicates if equation should be written as hidden, defaults to FALSE
desc	string equation description

---

Add scenario to the model

Description

Add scenario to the model

Usage

add_scenario(
  model,
  name = "expansion",
  origin = "baseline",
  origin_start = NA,
  origin_end = NA,
  shock
)

Arguments

model	SFC model object
name	string name of scenario, defaults to 'expansion'
origin	string name of origin scenario, from which the new scenario will be created, defaults to 'baseline'
origin_start	numeric period number from origin scenario from which the new scenario will begin
origin_end	numeric period number from origin scenario on which the new scenario will end
shock	shock object from create_shock() and add_shock()

Value

updated SFC model object containing added scenario

---

Add shock to shock object

Description

Add shock to shock object

Usage

add_shock(
  shock,
  variable,
  value = NA,
  rate = NA,
  absolute = NA,
  start = NA,
  end = NA,
  desc = ""
)

Arguments

shock	tibble from create_shock()
variable	string variable name
value	numeric, an explicit value or values for the variable, will be extended with last value
rate	numeric, multiplier to influence the original value of the variable
absolute	numeric, absolute value to influence the original value of the variable
start	numeric or date period number for the shock to take place, defaults to NA
end	numeric or date period number for the shock to take place, defaults to NA
desc	string variable description

Value

updated shock object containing added shock

---

Add variables to the model

Description

Add variables to the model

Usage

add_variable(model, ...)

Arguments

model	SFC model object
...	additional arguments passed to the function.

Value

updated SFC model object containing added variable

---

Add single variable to the model

Description

helper for add_variable()

Usage

add_variable_single(model, name, init = NA, desc = "")

Arguments

model	SFC model object
name	string name for added variable
init	numeric initial value, defaults to 1e-05
desc	string variable description

---

Change initial value of a variable

Description

Change initial value of a variable

Usage

change_init(model, name, value)

Arguments

model	SFC model object
name	string variable name
value	numeric value that will replace existing initial value

Value

updated SFC model object with new variable initial value

---

Create SFC model object

Description

Create SFC model object

Usage

create_model(name = "SFC model", template)

Arguments

name	string name for created SFC model object
template	string name of model template chosen from: 'SIM', 'PC', 'LP', 'REG', 'OPEN', 'BMW', 'BMWK', 'DIS', 'DISINF', 'SIMEX', 'PCEX' or user created SFC model object to be used as a template

Value

SFC model object

---

Create model with sensitivity scenarios

Description

Create model with sensitivity scenarios

Usage

create_sensitivity(model_pass, variable, lower = 0, upper = 1, step = 0.1)

Arguments

model_pass	SFC model object that will be used as a baseline for sensitivity calculation
variable	string name of the variable that will be used
lower	numeric lower bound value of the variable
upper	numeric upper bound value of the variable
step	numeric step between upper and lower bounds for the variable to take value

Value

SFC model object with sensitivity scenarios

---

Create shock used in add_scenario().

Description

Create shock used in add_scenario().

Usage

create_shock()

Value

shock object

---

Calculate 1 order lag difference of a variable in model

Description

Calculate 1 order lag difference of a variable in model

Usage

d(x)

Arguments

x	variable name

Details

this is a special function to be used exclusively in model equation strings e.g. "x = d(y) + z"

Value

difference

---

Network plot of the model

Description

Network plot of the model

Usage

plot_cycles(model, save_file = NULL)

Arguments

model	SFC model object created with create_model
save_file	name and path to save the plot as html file

Details

This function creates a representation of a model as a directed graph. Additionally it shows cycles in the model including these with lagged variables. Graph can be saved as html file.

Value

visNetwork object

Examples

model <- godley::create_model(name = "SFC model", template = "BMW")
plot_cycles(model)

---

Plot simulations of multiple variables in multiple scenarios

Description

Plot simulations of multiple variables in multiple scenarios

Usage

plot_simulation(
  model,
  scenario = "baseline",
  take_all = FALSE,
  from = NA,
  to = NA,
  expressions = "Y"
)

Arguments

model	SFC model object
scenario	vector of strings or single string name of scenario(s) from which take variables values, defaults to 'baseline'
take_all	logical indicating whether all scenarios containing the given scenario name string(s) should be used, defaults to FALSE
from	numeric period number from which the plot should start, defaults to maximum value
to	numeric period number on which the plot should end, defaults to minimum value
expressions	vector of strings or single string name of variable(s) expression(s) to plot, defaults to 'Y'

Value

plotly plot

---

Make initial matrix row for baseline scenario and prepare equations for simulate_scenario()

Description

Make initial matrix row for baseline scenario and prepare equations for simulate_scenario()

Usage

prepare(model, verbose = FALSE)

Arguments

model	SFC model object
verbose	logical to tell if additional model verbose should be displayed

Value

verified and prepared SFC model object

---

Simulate scenario of SFC model object

Description

Simulate scenario of SFC model object

Usage

simulate_scenario(
  model,
  scenario,
  periods = NA,
  start_date = NA,
  method = "Gauss",
  max_iter = 350,
  tol = 1e-05,
  hidden_tol = 0.1,
  verbose = FALSE
)

Arguments

model	SFC model object
scenario	vector of strings or single string name of scenario(s) to simulate
periods	numeric total number of rows (periods) in the model, defaults to 100
start_date	character date to begin the simulation in the format "yyyy-mm-dd"
method	string name of method used to find solution chosen from: 'Gauss', 'Newton', defaults to 'Gauss'
max_iter	numeric maximum iterations allowed per period, defaults to 350
tol	numeric tolerance accepted to determine convergence, defaults to 1e-05
hidden_tol	numeric error tolerance to accept the equality of hidden equations, defaults to 0.1.
verbose	logical to tell if additional model verbose should be displayed

Value

updated model containing simulated scenario(s)

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