R: Interactive plotting of graphs

tkplot {igraph} | R Documentation

## Interactive plotting of graphs

### Description

`tkplot` and its companion functions serve as an interactive graph drawing facility. Not all parameters of the plot can be changed interactively right now though, eg. the colors of vertices, edges, and also others have to be pre-defined.

### Usage

    tkplot(graph, canvas.width = 450, canvas.height = 450, ...)

    tk_close(tkp.id, window.close = TRUE)

    tk_off()

    tk_fit(tkp.id, width = NULL, height = NULL)

    tk_center(tkp.id)

    tk_reshape(tkp.id, newlayout, ..., params)

    tk_postscript(tkp.id)

    tk_coords(tkp.id, norm = FALSE)

    tk_set_coords(tkp.id, coords)

    tk_rotate(tkp.id, degree = NULL, rad = NULL)

    tk_canvas(tkp.id)

### Arguments

`graph` | The `graph` to plot.
`canvas.width, canvas.height` | The size of the tkplot drawing area.
`...` | Additional plotting parameters. See igraph.plotting for the complete list.
`tkp.id` | The id of the tkplot window to close/reshape/etc.
`window.close` | Leave this on the default value.
`width` | The width of the rectangle for generating new coordinates.
`height` | The height of the rectangle for generating new coordinates.
`newlayout` | The new layout, see the `layout` parameter of tkplot.
`params` | Extra parameters in a list, to pass to the layout function.
`norm` | Logical, should we norm the coordinates.
`coords` | Two-column numeric matrix, the new coordinates of the vertices, in absolute coordinates.
`degree` | The degree to rotate the plot.
`rad` | The degree to rotate the plot, in radian.

### Details

`tkplot` is an interactive graph drawing facility. It is not very well developed at this stage, but it should be still useful.

It's handling should be quite straightforward most of the time, here are some remarks and hints.

There are different popup menus, activated by the right mouse button, for vertices and edges. Both operate on the current selection if the vertex/edge under the cursor is part of the selection and operate on the vertex/edge under the cursor if it is not.

One selection can be active at a time, either a vertex or an edge selection. A vertex/edge can be added to a selection by holding the `control` key while clicking on it with the left mouse button. Doing this again deselect the vertex/edge.

Selections can be made also from the `Select` menu. The 'Select some vertices' dialog allows to give an expression for the vertices to be selected: this can be a list of numeric R expessions separated by commas, like '`1,2:10,12,14,15`' for example. Similarly in the 'Select some edges' dialog two such lists can be given and all edges connecting a vertex in the first list to one in the second list will be selected.

In the color dialog a color name like 'orange' or RGB notation can also be used.

The `tkplot` command creates a new Tk window with the graphical representation of `graph`. The command returns an integer number, the tkplot id. The other commands utilize this id to be able to query or manipulate the plot.

`tk_close` closes the Tk plot with id `tkp.id`.

`tk_off` closes all Tk plots.

`tk_fit` fits the plot to the given rectange (`width` and `height`), if some of these are `NULL` the actual phisical width od height of the plot window is used.

`tk_reshape` applies a new layout to the plot, its optional parameters will be collected to a list analogous to `layout.par`.

`tk_postscript` creates a dialog window for saving the plot in postscript format.

`tk_canvas` returns the Tk canvas object that belongs to a graph plot. The canvas can be directly manipulated then, eg. labels can be added, it could be saved to a file programatically, etc. See an example below.

`tk_coords` returns the coordinates of the vertices in a matrix. Each row corresponds to one vertex.

`tk_set_coords` sets the coordinates of the vertices. A two-column matrix specifies the new positions, with each row corresponding to a single vertex.

`tk_center` shifts the figure to the center of its plot window.

`tk_rotate` rotates the figure, its parameter can be given either in degrees or in radians.

### Value

`tkplot` returns an integer, the id of the plot, this can be used to manipulate it from the command line.

`tk_canvas` retuns `tkwin` object, the Tk canvas.

`tk_coords` returns a matrix with the coordinates.

`tk_close`, `tk_off`, `tk_fit`, `tk_reshape`, `tk_postscript`, `tk_center` and `tk_rotate` return `NULL` invisibly.

### Examples

    g <- make_ring(10)
    tkplot(g)

    ## Saving a tkplot() to a file programatically
    g <- make_star(10, center=10)
    E(g)$width <- sample(1:10, ecount(g), replace=TRUE)
    lay <- layout_nicely(g)

    id <- tkplot(g, layout=lay)
    canvas <- tk_canvas(id)
    tcltk::tkpostscript(canvas, file="/tmp/output.eps")
    tk_close(id)

    ## Setting the coordinates and adding a title label
    g <- make_ring(10)
    id <- tkplot(make_ring(10), canvas.width=450, canvas.height=500)

    canvas <- tk_canvas(id)
    padding <- 20
    coords <- norm_coords(layout_in_circle(g), 0+padding, 450-padding,
                          50+padding, 500-padding)
    tk_set_coords(id, coords)

    width <- as.numeric(tkcget(canvas, "-width"))
    height <- as.numeric(tkcget(canvas, "-height"))
    tkcreate(canvas, "text", width/2, 25, text="My title",
             justify="center", font=tcltk::tkfont.create(family="helvetica",
             size=20,weight="bold"))

### Author(s)

Gabor Csardi csardi.gabor@gmail.com

### See Also

`plot.igraph`, `layout`

[Package igraph version 1.2.6 Index]