Node connectivity {cheddar} | R Documentation |

Functions that report the connectivity of nodes in a food web.

IsBasalNode(community) IsTopLevelNode(community) IsIntermediateNode(community) IsIsolatedNode(community) IsConnectedNode(community) IsNonBasalNode(community) IsNonTopLevelNode(community) BasalNodes(community) TopLevelNodes(community) IntermediateNodes(community) IsolatedNodes(community) ConnectedNodes(community) NonTopLevelNodes(community) NonBasalNodes(community) FractionBasalNodes(community) FractionIntermediateNodes(community) FractionTopLevelNodes(community) FractionIsolatedNodes(community) FractionNonBasalNodes(community) FractionConnectedNodes(community) FractionNonTopLevelNodes(community)

`community` |
an object of class |

Each node in a community is defined as:

isolated | No resources or consumers, other than possibly itself |

basal | No resources and one or more consumers |

top-level | One or more resources and no consumers, other than possibly itself |

intermediate | Nodes not fitting any of the above categories |

These definitions allow the following additional definitions:

connected | basal, intermediate or top-level |

non-basal | isolated, intermediate or top-level |

non-top-level | isolated, basal or intermediate |

For each of the above seven definitions, ‘X’, there are three functions:
`IsX`

, `X`

and `FractionX`

.
The first returns a vector of `logical`

of length `NumberOfNodes`

;
values are `TRUE`

for nodes that fit the definition of ‘X’.
The second returns the names of nodes for which `IsX`

returns `TRUE`

.
The third returns the proportion of nodes in the community that fit the
definition of ‘X’.

Either a `logical`

vector of length `NumberOfNodes`

or a
vector of names.

Lawrence Hudson

`NumberOfNodes`

,
`Cannibals`

,
`IsCannibal`

,
`NumberOfTrophicLinks`

,
`PredationMatrix`

,
`Degree`

,
`InDegree`

,
`OutDegree`

,
`ResourcesByNode`

,
`ConsumersByNode`

,
`ResourcesOfNodes`

,
`ConsumersOfNodes`

data(TL84) # Assemble a table of node connectivity. Only one of each of the following # four properties is TRUE for each node. connectivity <- NPS(TL84, c('IsBasalNode', 'IsIsolatedNode', 'IsIntermediateNode', 'IsTopLevelNode')) connectivity # Each row sums to 1, confirming that exactly one of the columns in each row # is TRUE. all(1==rowSums(connectivity)) # These summations are 1 sum(FractionBasalNodes(TL84), FractionIntermediateNodes(TL84), FractionTopLevelNodes(TL84), FractionIsolatedNodes(TL84)) sum(FractionConnectedNodes(TL84), FractionIsolatedNodes(TL84)) sum(FractionBasalNodes(TL84), FractionNonBasalNodes(TL84)) sum(FractionTopLevelNodes(TL84), FractionNonTopLevelNodes(TL84))

[Package *cheddar* version 0.1-636 Index]