SpaDES (version 1.1.4)

SpaDES-package: Categorized overview of the SpaDES package

Description

This package allows implementation a variety of simulation-type models, with a focus on spatially explicit models. The core simulation components are built upon a discrete event simulation framework that facilitates modularity, and easily enables the user to include additional functionality by running user-built simulation modules. Included are numerous tools to visualize various spatial data formats, as well as non-spatial data.

Bug reports: https://github.com/PredictiveEcology/SpaDES/issues

Module repository: https://github.com/PredictiveEcology/SpaDES-modules

Wiki: https://github.com/PredictiveEcology/SpaDES/wiki

Arguments

1. Spatial discrete event simulation (<code>SpaDES</code>)

A collection of top-level functions for doing spatial discrete event simulation.

1.1 Simulations

There are two workhorse functions that initialize and run a simulation:

ll{ simInit Initialize a new simulation spades Run a discrete event simulation experiment Run multiple spades calls }

1.2 Events

Within a module, important simulation functions include:

ll{ scheduleEvent Schedule a simulation event removeEvent Remove an event from the simulation queue (not yet implemented) }

1.2 <code>simList</code> methods

Collections of commonly used functions to retrieve or set slots (and their elements) of a simList object are summarized further below.

1.2.1 Simulation parameters

Accessor functions for the params slot and its elements.

Commonly used: ll{ globals List of global simulation parameters. objs List of objects referenced by the simulation environment. params Nested list of all simulation parameter. }

Advanced use: lll{ Accessor method Module Description checkpointFile .checkpoint Name of the checkpoint file. (advanced) checkpointInterval .checkpoint The simulation checkpoint interval. (advanced) outputPath NA Global simulation output path. (advanced) inputPath NA Global simulation input path. (advanced) modulePath NA Global module path. (advanced) paths NA Show all paths (input, output, module). (advanced) progressType .progress Type of graphical progress bar used. (advanced) progressInterval .progress Interval for the progress bar. (advanced) }

1.2.2 Simulation times

Accessor functions for the simtimes slot and its elements.

ll{ time Current simulation time, in units of longest module. start Simulation start time, in units of longest module. end Simulation end time, in units of longest module. times List of all simulation times (current, start, end), in units of longest module.. }

1.2.3 Simulation event queues

Accessor functions for the events and completed slots. By default, the event lists are shown when the simList object is printed, thus most users will not require direct use of these methods.

ll{ events Scheduled simulation events (the event queue). (advanced) current Currently executing event. (advanced) completed Completed simulation events. (advanced) }

1.2.4 Modules and dependencies

Accessor functions for the depends, modules, and .loadOrder slots. These are included for advanced users.

ll{ depends List of simulation module dependencies. (advanced) modules List of simulation modules to be loaded. (advanced) inputs List of loaded objects used in simulation. (advanced) outputs List of objects to save during simulation. (advanced) }

1.2.5 Copy simList

The simList has a slot with all objects, called ".envir". This is an environment. In R, environments use pass-by-reference semantics, which means that copying an simList object using normal R assignment operation, e.g., sim2 <- sim1, will not copy the objects contained within the .envir slot. The two objects sim1 and sim2 will shared identical objects within that slot. Sometimes, this not desired, and a true copy is required.

ll{ copy Deep copy of a simList. (advanced) }

1.3 Module operations

Modules are the basic unit of SpaDES. These are generally created and stored locally, or are downloaded from remote repositories, including our https://github.com/PredictiveEcology/SpaDES-modules{SpaDES-modules repository on GitHub}.

ll{ downloadModule Open all modules nested within a base directory getModuleVersion Get the latest module version # from module repository newModule Create new module from template newModuleDocumentation Create empty documentation for a new module openModules Open all modules nested within a base directory moduleMetadata Shows the default values for a module zipModule Zip a module and its associated files }

1.4 Module dependencies

Once a set of modules have been chosen, the dependency information is automatically calculated once simInit is run. There are several functions to assist with dependency information:

ll{ depsEdgeList Build edge list for module dependency graph depsGraph Build a module dependency graph using igraph }

1.5 Exported <code>SpaDES</code> object classes

ll{ simList The 'simList' class }

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2 Module functions

A collection of functions that help with making modules, in addition to all the other R packages and code.

2.1 Module metadata

Each module requires several items to be defined. These comprise the metadata for that module (including default parmater specifications), and are currently written at the top of the module's .R file.

ll{ defineModule Define the module metadata defineParameter Specify a parameter's name, value and set a default }

2.2 Spatial spreading

Spatial contagion is a key phenomenon for spatially explicit simulation models. Contagion can be modelled using discrete approaches or continuous approaches. Several SpaDES functions assist with these:

ll{ spread Contagious cellular automata adj An optimized (i.e., faster) version of adjacent cir Identify pixels in a circle around a SpatialPoints* object }

2.3 Spatial agent methods

Agents have several methods and functions specific to them:

ll{ crw Simple correlated random walk function heading Determines the heading between SpatialPoints* makeLines Makes SpatialLines object for, e.g., drawing arrows move A meta function that can currently only take "crw" specificNumPerPatch Initiate a specific number of agents per patch }

2.4 GIS operations

In addition to the vast amount of GIS operations available in R (mostly from contributed packages such as sp, raster, maps, maptools and many others), we provide the following GIS-related functions: ll{ equalExtent Assess whether a list of extents are all equal }

2.5 Map-reduce - type operations

These functions convert between reduced and mapped representations of the same data. This allows compact representation of, e.g., rasters that have many individual pixels that share identical information. ll{ rasterizeReduced Convert reduced representation to full raster }

2.6 Colors in Raster* objects

We likely will not want the default colours for every map. Here are several helper functions to add to, set and get colors of Raster* objects: ll{ setColors Set colours for plotting Raster* objects getColors Get colours in a Raster* objects }

2.7 Random Map Generation

It is often useful to build dummy maps with which to build simulation models before all data are available. These dummy maps can later be replaced with actual data maps.

ll{ gaussMap Creates a random map using gaussian random fields randomPolygons Creates a random polygon with specified number of classes }

2.8 Checking for the existence of objects

SpaDES modules will often require the existence of objects in the simList. These are helpers for assessing this:

ll{ checkObject Check for a existence of an object within a simList checkPath Checks the specified filepath for formatting consistencies }

2.9 SELES-type approach to simulation

These functions are essentially skeletons and are not fully implemented. They are intended to make translations from http://www.gowlland.ca/{SELES}. You must know how to use SELES for these to be useful: ll{ agentLocation Agent location initiateAgents Initiate agents into a SpatialPointsDataFrame numAgents Number of agents probInit Probability of intiating an agent or event transitions Transition probability }

2.10 Miscellaneous

Functions that may be useful within a SpaDES context ll{ inRange Test whether a number lies within range [a,b] layerNames Get layer names for numerous object classes loadPackages Simple wrapper for loading packages nlayers Return number of layers paddedFloatToChar Wrapper for padding (e.g., zeros) floating numbers to character updateList Update values in a named list }

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3 Plotting

There are several user-accessible plotting functions that are optimized for modularity and speed of plotting:

Commonly used: ll{ Plot The workhorse plotting function }

Simulation diagrams: ll{ eventDiagram Gantt chart representing the events in a completed simulation. moduleDiagram Network diagram of simplified module (object) dependencies. objectDiagram Sequence diagram of detailed object dependencies. }

Other useful plotting functions: ll{ clearPlot Helpful for resolving many errors clickValues Extract values from a raster object at the mouse click location(s) clickExtent Zoom into a raster or polygon map that was plotted with Plot clickCoordinates Get the coordinates, in map units, under mouse click dev Specify which device to plot on, making a non-RStudio one as default newPlot Open a new default plotting device rePlot Replots all elements of device for refreshing or moving plot }

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4 File operations

In addition to R's file operations, we have added several here to aid in bulk loading and saving of files for simulation purposes:

ll{ getFileName Get the name of current file loadFiles Load simulation objects according to a filelist rasterToMemory Read a raster from file to RAM saveFiles Save simulation objects according to outputs and params }

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5 Sample data and modules included in package

Five maps and three modules are included within the SpaDES package

5.1 Data

Several dummy data sets are included for testing of functionality ll{ spadesMaps Help showing included maps }

5.2 Modules

Several dummy modules are included for testing of functionality. These can be found with file.path(find.package("SpaDES"), "sampleModules") ll{ randomLandscapes Imports, updates, and plots several raster map layers caribouMovement A simple agent-based (a.k.a., individual-based) model fireSpread A simple model of a spatial spread process }