如何将文本添加到R中的网络图中？

Question

我现在用的是包networkDynamic形象化2个网络演进，我想补充，接近每个网络都有一个简单的图例（文字几句话）。我找不到这样做的方法。

在networkDynamic包，该函数render.animation使用plot.network（从封装network）来渲染每个帧，然后编译不同的帧转换为动画。

plot.network参数可以传递给render.animation，所以问题似乎归结为将文本添加到使用plot.network生成的图中，但似乎没有在指定坐标上添加文本的方式。

与正常的plot我会使用text函数，但是有没有办法将这个函数包含到plot.network参数？

Answer 1

render.animation处于ndtv包的功能。你将不得不创建一个基于render.animation定制render.animation2功能。在下面的函数中，我添加了一行到render.animation函数。我添加mtext之后的每个plot.network呼叫（见从端约20线）。您可以将其更改为text而不是mtext。

render.animation2 <- function (net, render.par = list(tween.frames = 10, show.time = TRUE, 
    show.stats = NULL, extraPlotCmds = NULL, initial.coords = 0), 
    plot.par = list(bg = "white"), ani.options = list(interval = 0.1), 
    render.cache = c("plot.list", "none"), verbose = TRUE, ...) 
{ 
    if (!is.network(net)) { 
     stop("render.animation requires the first argument to be a network object") 
    } 
    if (is.null(render.par)) { 
     stop("render.animation is missing the 'render.par' argument (a list of rendering parameters).") 
    } 
    if (is.null(render.par$tween.frames)) { 
     render.par$tween.frames <- 10 
    } 
    if (is.null(render.par$show.time)) { 
     render.par$show.time <- TRUE 
    } 
    if (is.null(render.par$initial.coords)) { 
     render.par$initial.coords <- matrix(0, ncol = 2, nrow = network.size(net)) 
    } 
    if (!all(c("animation.x.active", "animation.y.active") %in% 
     list.vertex.attributes(net))) { 
     net <- compute.animation(net, verbose = verbose) 
    } 
    externalDevice <- FALSE 
    doRStudioHack <- TRUE 
    if (!is.null(render.par$do_RStudio_plot_hack)) { 
     doRStudioHack <- render.par$do_RStudio_plot_hack 
    } 
    if (!is.function(options()$device)) { 
     if (names(dev.cur()) == "RStudioGD" & doRStudioHack) { 
      message("RStudio's graphics device is not well supported by ndtv, attempting to open another type of plot window") 
      if (.Platform$OS.type == "windows") { 
       windows() 
      } 
      else if (length(grep(R.version$platform, pattern = "apple")) > 
       0) { 
       quartz() 
      } 
      else { 
       x11() 
      } 
      externalDevice <- TRUE 
     } 
    } 
    if (par("bg") == "transparent" & is.null(plot.par$bg)) { 
     plot.par$bg <- "white" 
    } 
    origPar <- par(plot.par) 
    oopts <- ani.options(ani.options) 
    slice.par <- get.network.attribute(net, "slice.par") 
    if (is.null(slice.par)) { 
     stop("render.animation can not locate the 'slice.par' list of parameters in the input network object") 
    } 
    render.cache <- match.arg(render.cache) 
    plot_params <- list(...) 
    if (is.null(plot_params$label)) { 
     plot_params$label <- function(slice) { 
      network.vertex.names(slice) 
     } 
    } 
    if (is.null(plot_params$xlab) & render.par$show.time) { 
     plot_params$xlab <- function(onset, terminus) { 
      ifelse(onset == terminus, paste("t=", onset, sep = ""), 
       paste("t=", onset, "-", terminus, sep = "")) 
     } 
    } 
    if (!is.null(render.par$show.stats) && render.par$show.stats != 
     FALSE) { 
     if (render.par$show.time) { 
      plot_params$xlab <- eval(parse(text = paste("function(slice,onset,terminus){stats<-summary.statistics.network(slice", 
       render.par$show.stats, ")\n return(paste('t=',onset,'-',terminus,' ',paste(rbind(names(stats),stats),collapse=':'),sep='')) }", 
       sep = ""))) 
     } 
     else { 
      plot_params$xlab <- eval(parse(text = paste("function(slice){stats<-summary.statistics.network(slice", 
       render.par$show.stats, ")\n return(paste(rbind(names(stats),stats),collapse=':')) }", 
       sep = ""))) 
     } 
    } 
    if (is.null(plot_params$jitter)) { 
     plot_params$jitter <- FALSE 
    } 
    interp.fun <- coord.interp.smoothstep 
    starts <- seq(from = slice.par$start, to = slice.par$end, 
     by = slice.par$interval) 
    ends <- seq(from = slice.par$start + slice.par$aggregate.dur, 
     to = slice.par$end + slice.par$aggregate.dur, by = slice.par$interval) 
    xmin <- aggregate.vertex.attribute.active(net, "animation.x", 
     min) 
    xmax <- aggregate.vertex.attribute.active(net, "animation.x", 
     max) 
    ymin <- aggregate.vertex.attribute.active(net, "animation.y", 
     min) 
    ymax <- aggregate.vertex.attribute.active(net, "animation.y", 
     max) 
    if (is.null(plot_params$xlim)) { 
     if (xmin == xmax) { 
      xmax <- xmin + 1 
      xmin <- xmin - 1 
     } 
     plot_params$xlim <- c(xmin, xmax) 
    } 
    if (is.null(plot_params$ylim)) { 
     if (ymin == ymax) { 
      ymax <- ymin + 1 
      ymin <- ymin - 1 
     } 
     plot_params$ylim <- c(ymin, ymax) 
    } 
    if (is.numeric(render.par$initial.coords)) { 
     coords <- matrix(render.par$initial.coords, ncol = 2, 
      nrow = network.size(net)) 
    } 
    slice <- network.collapse(net, starts[1], ends[1], rule = slice.par$rule, 
     rm.time.info = FALSE) 
    activev <- is.active(net, starts[1], ends[1], v = seq_len(network.size(net)), 
     rule = if (slice.par$rule != "all") { 
      "any" 
     }) 
    if (length(slice) > 0 & network.size(slice) > 0) { 
     coords[activev, 1] <- get.vertex.attribute(slice, "animation.x") 
     coords[activev, 2] <- get.vertex.attribute(slice, "animation.y") 
    } 
    coords2 <- coords 
    if (render.cache == "plot.list") { 
     ani.record(reset = TRUE) 
    } 
    for (s in 1:length(starts)) { 
     if (verbose) { 
      print(paste("rendering", render.par$tween.frames, 
       "frames for slice", s - 1)) 
     } 
     slice <- network.collapse(net, starts[s], ends[s], rule = slice.par$rule, 
      rm.time.info = FALSE) 
     activev <- is.active(net, starts[s], ends[s], v = seq_len(network.size(net)), 
      rule = if (slice.par$rule != "all") { 
       "any" 
      }) 
     if (length(slice) > 0 & network.size(slice) > 0) { 
      evald_params <- .evaluate_plot_params(plot_params = plot_params, 
       net = net, slice = slice, s = s, onset = starts[s], 
       terminus = ends[s]) 
      for (t in 1:render.par$tween.frames) { 
       coords2[activev, 1] <- get.vertex.attribute(slice, 
        "animation.x") 
       coords2[activev, 2] <- get.vertex.attribute(slice, 
        "animation.y") 
       tweenCoords <- interp.fun(coords, coords2, t, 
        render.par$tween.frames) 
       plot_args <- list(x = slice, coord = tweenCoords[activev, 
        , drop = FALSE]) 
       plot_args <- c(plot_args, evald_params) 
       do.call(plot.network, plot_args) 
       mtext("my text\n on two lines", side = 3) #my.legend 
       if (!is.null(render.par$extraPlotCmds)) { 
        eval(render.par$extraPlotCmds) 
       } 
       if (render.cache == "plot.list") { 
        ani.record() 
       } 
      } 
      coords <- coords2 
     } 
     else { 
      evald_params <- .evaluate_plot_params(plot_params = plot_params, 
       net = net, slice = slice, s = s, onset = starts[s], 
       terminus = ends[s]) 
      if (render.par$show.time) { 
       xlab <- evald_params$xlab 
      } 
      else { 
       xlab <- NULL 
      } 
      singlenet <- network.initialize(1) 
      for (t in 1:render.par$tween.frames) { 
       plot.network(singlenet, vertex.cex = 0, xlab = xlab) 
       if (!is.null(render.par$extraPlotCmds)) { 
        eval(render.par$extraPlotCmds) 
       } 
       if (render.cache == "plot.list") { 
        ani.record() 
       } 
      } 
     } 
    } 
    par(origPar) 
    if (externalDevice) { 
     dev.off() 
    } 
} 

它是那么重要的新功能render.animation2分配给ndtv命名空间。如果你不这样做，它将会崩溃，因为render.animation指的是只能在其自己的命名空间中找到的函数。

environment(render.animation2) <- asNamespace('ndtv') 
environment(render.animation) #<environment: namespace:ndtv> 
environment(render.animation2) #<environment: namespace:ndtv> 

使用，render.animation2，然后你会得到你的传奇印在动画的每张幻灯片。

require(ndtv) 
triangle <- network.initialize(3) # create a toy network 
add.edge(triangle,1,2) 
# add an edge between vertices 1 and 2 
add.edge(triangle,2,3) 
# add a more edges 
activate.edges(triangle,at=1) # turn on all edges at time 1 only 
activate.edges(triangle,onset=2, terminus=3, 
e=get.edgeIDs(triangle,v=1,alter=2)) 
add.edges.active(triangle,onset=4, length=2,tail=3,head=1) 
render.animation2(triangle) #custom function 
ani.replay() 

这里的最后一张幻灯片的样子动画：

Answer 2

如果你只需要在文本中添加几行，就可以通过标准的阴谋论点main（主标题）或xlab（用于x轴标题）。可以用换行逃逸分隔行“\ n”个

library(ndtv) 
data(short.stergm.sim) 
render.animation(short.stergm.sim,main='hello\nworld') 

也可以绘制其他图形元素（如legend或text或映射）使用extraPlotCmds参数render.animation。例如，如果你想绘制的“Hello World”，在蓝色的使用text coordiantes 0,0您可以在expression把它包起来，并通过render.par

render.animation(short.stergm.sim, 
       render.par=list(extraPlotCmds=expression(
            text(0,0,'hello\nworld',col='blue') 
           )) 
       ) 

额外的绘图命令传递每一帧都会评估作为网络渲染