Render igraph arrows

Source: R/jam-igraph-internals.R

Render igraph arrows

jam_igraph_arrows(
  x1,
  y1,
  x2,
  y2,
  code = 2,
  size = 1,
  width = 1,
  open = TRUE,
  sh.adj = 0.1,
  sh.lwd = 1,
  sh.col = if (is.R()) par("fg") else 1,
  sh.lty = 1,
  h.col = sh.col,
  h.col.bo = sh.col,
  h.lwd = sh.lwd,
  h.lty = sh.lty,
  arrows_only = FALSE,
  curved = FALSE,
  verbose = FALSE
)

Arguments

x1, y1, x2, y2

numeric coordinates for initial and final x and y coordinates.

code

integer indicating the position of arrow:

  • code=1 arrow is positioned on the line end

  • code=2 arrow is positioned on the line start

  • code=3 arrow is positioned on both ends of the line

size

numeric scaled size of the arrow head, which is applied to both the length and width of the arrow head.

width

numeric scalar for the arrow head width, which is only applied to the relative arrow width.

open

logical indicating whether the arrow head should be a filled polygon, otherwise only the outer "V" lines are drawn.

sh.adj

numeric adjustment for segment length, where:

  • sh.adj=0 will extend the edge line (underneath the arrow head) to the end of the line

  • sh.adj=1 will extend the edge line only to the base of the arrow head

  • sh.adj=1.1 will leave a gap approximately 10% the arrow head length, between the edge line and the start of the arrow head.

sh.lwd

numeric line width of main segment edge line

sh.col

character color of main segment edge line

sh.lty

numeric line type of main segment edge line

h.col, h.col.bo

character arrow head color and arrow head border color, respectively.

h.lwd

numeric arrow head line width

h.lty

numeric arrow head line type

arrows_only

logical indicating whether to draw only arrows, or arrows_only=FALSE to draw arrows and edge lines.

curved

logical indicating whether to draw curved edges

verbose

logical indicating whether to print verbose output.

Details

This function is a mimic of the internal igraph:::igraph.Arrows() which is not permitted to be called directly for CRAN-approved R packages.

See also

Other jam igraph internal functions: default_igraph_values(), get_igraph_arrow_mode(), parse_igraph_plot_params()

Examples

plot(NULL, xlim=c(-3, 3), ylim=c(-4, 4), type="n", xlab="", ylab="", bty="n")
jam_igraph_arrows(-2, 3, 2, 3, code=1, open=FALSE, sh.col="blue", sh.lwd=2)
#> $lab.x
#> [1] -0.6666667
#> 
#> $lab.y
#> [1] 3
#> 
jam_igraph_arrows(-2, 2, 2, 2, code=2, open=FALSE, sh.col="red", sh.lwd=2)
#> $lab.x
#> [1] -0.6666667
#> 
#> $lab.y
#> [1] 2
#> 
jam_igraph_arrows(-2, 1, 2, 1, code=3, open=FALSE, sh.col="gold", sh.lwd=2)
#> $lab.x
#> [1] -0.6666667
#> 
#> $lab.y
#> [1] 1
#> 
jam_igraph_arrows(-2, 0, 2, 0, code=3, arrows_only=TRUE, open=FALSE, sh.col="purple4", sh.lwd=2)
#> $lab.x
#> [1] -0.6666667
#> 
#> $lab.y
#> [1] 3.265725e-16
#> 

jam_igraph_arrows(-2, -1, 2, -1, code=1, open=FALSE, sh.col="blue", h.col="#FF000055", sh.lwd=2, size=2, sh.adj=0.1)
#> $lab.x
#> [1] -0.6666667
#> 
#> $lab.y
#> [1] -1
#> 
jam_igraph_arrows(-2, -2, 2, -2, code=1, open=FALSE, sh.col="blue", h.col="#FF000055", sh.lwd=2, size=2, sh.adj=1.1)
#> $lab.x
#> [1] -0.6666667
#> 
#> $lab.y
#> [1] -2
#> 
jam_igraph_arrows(-2, -3, 2, -3, code=2, open=FALSE, sh.col="blue", h.col="#FF000055", sh.lwd=2, size=2, sh.adj=1.1)
#> $lab.x
#> [1] -0.6666667
#> 
#> $lab.y
#> [1] -3
#> 
jam_igraph_arrows(-2, -4, 2, -4, code=3, open=FALSE, sh.col="blue", h.col="#FF000055", sh.lwd=2, size=2, sh.adj=1.1)
#> $lab.x
#> [1] -0.6666667
#> 
#> $lab.y
#> [1] -4
#> 
text(x=rep(0, 8), y=seq(from=3, to=-4)+0.2,
   labels=c("code=1",
      "code=2",
      "code=3",
      "code=3, arrows_only=TRUE",
      "code=1, size=2, sh.adj=0.1",
      "code=1, size=2, sh.adj=1.1",
      "code=2, size=2, sh.adj=1.1",
      "code=3, size=2, sh.adj=1.1"))