network_layout.R

network_layout <- function(n, rotate = 0, label = NULL, weight = 2, loc = NA){
  tau <- seq(0, 2*pi, length.out = n+1)[1:n] + rotate
  nodes <- tibble::tibble(idx = 1:n,
                          x = sin(tau),
                          y = cos(tau))

  edges <- purrr::cross_df(tibble::tibble(pop1 = nodes$idx,
                                          pop2 = nodes$idx), .filter = `>=`) %>%
    dplyr::arrange(pop1) %>%
    dplyr::left_join(., nodes %>% select(idx, x,y) %>% purrr::set_names(., nm = c('pop1','x','y'))) %>%
    dplyr::left_join(., nodes %>% select(idx, x,y) %>% purrr::set_names(., nm = c('pop2','xend','yend'))) %>%
    dplyr::mutate(idx = row_number(),
                  xmid_shift = (x*weight + xend)/(1*weight+1),
                  ymid_shift = (y*weight + yend)/(1*weight+1),
                  xmid = (x+xend)/2,
                  ymid = (y+yend)/2) %>%
    dplyr::select(idx, pop1:ymid)

  if(!is.null(label)){
    nodes <- nodes %>%
      dplyr::mutate(label = label)

    edges <- edges %>%
      dplyr::mutate(lab1 = label[pop1],
                    lab2 = label[pop2],
                    run = stringr::str_c(lab1,'-',lab2))
  }

  tibble::tibble(loc = loc, nodes = list(nodes), edges = list(edges))
}

plot_network <- function(loc, nodes, edges, asp = .8, sep = 0, node_lab_shift = 0){

  loc_edge <- c(bel = .68, hon = .66, pan = .82) -.03
  clr_prep <- (scales::colour_ramp(c("black",
                                     "red")))(c(0.4, 1))
  clrs <- colorRampPalette(clr_prep)(max(edges$idx))
  p <- nodes %>% ggplot(aes(x, y)) +
    coord_fixed(ratio = asp) +
    geom_segment(data = edges,
                 aes(xend = xend, yend = yend),
                 size = .1,
                 color = "red") +
    scale_size(limits = c(0, 1), range = c(.1, 2))
  for (k in nodes$idx) {
    cat( nodes$label[k])
    p <- p + plot_fish(names = nodes$label[k],
                           x = nodes$x[k], y = nodes$y[k], height = .7, width = .7)
  }
  p + geom_label(data = edges, aes(x = xmid_shift + sign(xmid_shift) * sep,
                                   y = ymid_shift + sign(ymid_shift) * sep * asp,
                                   label = "x"),
                 color = "red",
                 label.padding = unit(1, "pt"),
                 label.size = 0,
                 size = 2 * .5 /ggplot2::.pt) +
      scale_x_continuous(limits = c(-1.3, 1.3),
                       expand = c(0, 0)) +
    scale_y_continuous(expand = c(0, 0.1)) +
    theme_void()
}