R: plots a web

plotweb {diagram} | R Documentation

## plots a web

### Description

plots a web, based on a flow matrix

### Usage

    plotweb(flowmat, names = NULL, lab.size = 1.5, add = FALSE,
            fig.size = 1.3, main = "", sub = "", sub2 = "",
            log = FALSE, mar = c(2, 2, 2, 2),
            nullflow = NULL, minflow = NULL, maxflow = NULL,
            legend = TRUE, leg.digit = 5, leg.title = NULL,
            lcol = "black", arr.col = "black",
            val = FALSE, val.digit = 5, val.size = 0.6, val.col = "red",
            val.title = NULL, val.ncol = 1,
            budget = FALSE, bud.digit = 5, bud.size = 0.6,
            bud.title = "budget", bud.ncol = 1,
            maxarrow = 10, minarrow = 1, length = 0.1, dcirc = 1.2, bty = "o", ...)

### Arguments

`flowmat` | flow matrix, rows=flow *from*, columns=flow *to*.
`names` | string vector with the names of components.
`lab.size` | relative size of name label text.
`add` | start a new plot (`FALSE`), or add to current (`TRUE`).
`fig.size` | if `add = FALSE`: relative size of figure.
`main` | if `add = FALSE`: main title.
`sub` | if `add = FALSE`: sub title.
`sub2` | if`add = FALSE`: title in bottom.
`log` | logical indicating whether to scale the flow values logarithmically.
`mar` | the figure margins.
`nullflow` | either one value or a two-valued vector; if flow < nullflow[1] or flow > nullflow[2] (if two values): flow is assumed = 0 and the arrow is not drawn.
`minflow` | flowvalue corresponding to minimum arrow thickness.
`maxflow` | flowvalue corresponding to maximum arrow thickness.
`legend` | logical indicating whether to add a legend with arrow thickness.
`leg.digit` | nr of digits for writing legend - only if `legend` = TRUE.
`leg.title` | title for arrow legend, e.g to give units - only if `legend` =TRUE.
`lcol` | line color of arrow - not used.
`arr.col` | arrow color. One value or a matrix, with same dimensions as flowmat; if a matrix, each arrow can have a different color.
`val` | logical indicating whether to write flow values as a legend.
`val.digit` | nr of digits for writing values - only if `val =TRUE`.
`val.size` | relative size for writing values - only if `val =TRUE`.
`val.col` | color for writing values - only if `val =TRUE`.
`val.title` | title for values legend - only if `val =TRUE`.
`val.ncol` | number of columns for writing values - only if `val =TRUE`.
`budget` | logical indicating whether to calculate budget (sum of flows in - sum of flows out) per component.
`bud.digit` | nr of digits for writing budget - only if `budget =TRUE`.
`bud.size` | relative size for writing budget - only if `budget =TRUE`.
`bud.title` | title for budget legend - only if `budget =TRUE`.
`bud.ncol` | number of columns for writing budget - only if `budget =TRUE`.
`maxarrow` | maximal thickness of arrow.
`minarrow` | minimal thickness of arrow.
`length` | length of the edges of the arrow head (in inches).
`dcirc` | if cannibalism (flow from i to i), offset of circular 'arrow' - if `dcirc` = 0:no circle drawn.
`bty` | the type of box to be drawn around the legends (`legend`, `val`, `budget`). The allowed values are "o" (the default) and "n".
`...` | extra arguments passed to R-function arrows.

### Details

This function is less flexible than function `plotmat`

It is meant for visualisation of food web flows, that are inputted as a flow matrix.

It displays the elements on a circle, and, where there is a mass flow, two elements are connected,

the magnitude of the web flows is reflected by the thickness of the arrow

Note that the input matrices from function `plotmat` and `plotweb` are transposed.

### Author(s)

Karline Soetaert <karline.soetaert@nioz.nl>

### See Also

`plotmat`,

`Rigaweb`, `Takapotoweb`

try: demo(plotweb)

### Examples

    plotweb(Rigaweb, main = "Gulf of Riga food web",
            sub = "mgC/m3/d", val = TRUE)

    ArrCol <- Rigaweb
    ArrCol[] <- "black"
    ArrCol[,"Sedimentation"] <- "green"

    plotweb(Rigaweb, main = "Gulf of Riga food web",
            sub = "mgC/m3/d", val = FALSE, arr.col = ArrCol)

    plotweb(diag(20), main = "plotweb")

[Package diagram version 1.6.4 Index]