sdRepository: sdsim Models Repository List

In EmbrapaInformaticaAgropecuaria/sdsim: System Dynamics Model Simulator for Initial Value Problems of ODE

Description

Show the complete list of models stored in the package sdsim repository. Use the function sdLoadModel with file = 'modelID' and repository = TRUE to load a model from the sdsim repository.

Usage

sdRepository()

Details

Models ID and description:

Arenstorf

The Arenstorf problem, from Astronomy, describes the movement of a small body orbiting regularly around two larger objects, such as a spacecraft going between the Earth and the Moon.

The two large bodies have mass m1 and m2 and move in a circular rotation (coordinates y1 and y2) in a plane, while the third body has negligible mass and is moving in the same plane.

It was necessary to solve this problem in order to determine the path that the Apollo spacecraft had to take in its journey between the Earth and the Moon. The problem was solved by Arenstorf and now it is an often used test problem for non-stiff solvers.

Source: Soetaert K., Cash J., Mazzia F. - Solving Differential Equations in R - Springer(2012)

BouncingBall

Simulates a bouncing ball specified by its position above the ground (height). The ball is thrown vertically, from the ground (height(0) = 0 meter), with initial velocity (speed) of 10 meter / second.

As the ball hits the ground, it bounces. This causes a sudden change in the value of the ball's velocity (a sign-reversal and reduction of its magnitude directly proportional to the coefficient of restitution (k)).

Source: Soetaert K., Cash J., Mazzia F. - Solving Differential Equations in R - Springer(2012)

Customer

In order to demonstrate how a system dynamics model is constructed, a one-stock model of an organization's customer base is modeled.

Given that the customer base is an accumulation, it can be modeled as a stock. The inflow is recruits, and the outflow are losses, also known as the churn rate. The goal of organizations is to limit the losses and maximize the recruits, in order to maintain increasing customers levels, and therefore support company growth.

Source: Jim Duggan, System Dynamics Modeling with R (2016).

GrowthConstrained

The model captures the growth and decline dynamics of a company discovering a new oil field, where the stock of oil could potentially last for up to 200 years.

Source: Jim Duggan, System Dynamics Modeling with R (2016).

RigidBody

A standard test problem for non-stiff solvers, as proposed by Krogh. It describes the Euler equations of a rigid body without external forces. The three dependent variables (x , y , z) are the coordinates of the rotation vector, while I1, I2 and I3 are the principal moments of inertia.

Source: Soetaert K., Cash J., Mazzia F. - Solving Differential Equations in R-Springer(2012)

Examples

## Show the models ID present in the sdsim repository
sdRepository()

## Load the Arenstorf model from the sdsim repository 
arenstorf <- sdLoadModel(file = "Arenstorf", repository = TRUE) 

# validate the model, simulate it and plot the coordinates result
arenstorf$verifyModel(verbose = TRUE)
outaren <- sdSimulate(arenstorf)
outaren$plot("y1 ~ y2")

EmbrapaInformaticaAgropecuaria/sdsim documentation built on May 10, 2019, 9:58 a.m.