geo.change.attr: Change values of a node attribute

In thibautjombart/geograph: Walking through the geographic space using graphs

Change values of a node attribute

Description

The functions geo.change.attr changes values of a given node attribute for a set of selected nodes of a gGraph object.

Usage

geo.change.attr(
  x,
  mode = c("points", "area"),
  attr.name,
  attr.value,
  only.name = NULL,
  only.value = NULL,
  newCol = "black",
  restore.edges = FALSE,
  refObj = "rawgraph.40k"
)

Arguments

x	a valid gGraph object.
mode	a character string indicating whether selected nodes are clicked one by one ('points') or by defining a rectangular area ('area').
attr.name	the name of the node attribute to be modified.
attr.value	the new value of attribute assigned to selected nodes.
only.name	(optional) in area mode, the name of a node attribute to add an extra selection criterion. See details.
only.value	(optional) in area mode, and if only.name is specified, the values of only.name that can be selected. See details.
newCol	a character string giving the new color for the attribute value.
restore.edges	a logical indicating whether edges stemming from the modified nodes should be re-added to the graph, using refObj as a reference. This is useful when connectivity is to be redefined using setCosts for nodes that were previously disconnected.
refObj	a character string or a gGraph object, used as reference when re-adding edges. If a character string is provided, it must match one of the following dataset: 'rawgraph.10k', 'rawgraph.40k'.

Details

The argument only.name allows one to perform a more accurate selection of nodes whose attribute is changed, by specifying values (only.value) of an attribute (only.name) that can be selected. For instance, one may want to define new attributes for nodes of worldgraph.10k that are exclusively on land: this would be done by specifying only.name="habitat" and only.value="land".

Value

A gGraph object with modified node attributes.

Examples

## Not run: 
plot(worldgraph.10k, reset = TRUE)

## have to click here for an area
## all nodes are modified in the area
x <- geo.change.attr(worldgraph.10k, mode = "area", attr.name = "habitat", attr.value = "fancy
habitat", newCol = "pink") # modify selected area

plot(x, reset = TRUE) # modification in the whole selected area

## have to click here for an area
## only nodes on land are modified
x <- geo.change.attr(x, mode = "area", attr.name = "habitat", attr.value = "fancy2
habitat", newCol = "purple", only.name = "habitat", only.value = "land")

plot(x, reset = TRUE) # modification in the whole selected area

## End(Not run)

thibautjombart/geograph documentation built on April 13, 2025, 9:39 a.m.