ggraph/ggplot2 中的手动图例 [R]

除了这个帖子 https://stackoverflow.com/questions/51569831/how-to-draw-graph-corresponding-with-its-attributes-in-ggraph-r，在这里我提出新问题如何调整由ggraph.

以下是生成当前绘图的脚本：

    ## Packages
    library(igraph)
    library(tidygraph)
    library(ggraph)
    library(ggplot2)
    library(tidyverse)

    ## Edge and node
    edge <- data.frame(from=c(0,0,0,0,1,2,3),
                       to=c(0,1,2,3,0,0,0),
                       weight=c(1,3,1,1,3,1,1))
    node <- data.frame(id=c(0,1,2,3),
                       p=c(9,1,0,0),
                       w=c(0,2,0,0),
                       s=c(0,1,1,1),
                       size=c(9,3,1,1),
                       gr=c(0,1,1,2))

    ## Load data frames as tbl_graph class
    edge <- edge %>% mutate(from=from+1,to=to+1)
    net <- tbl_graph(nodes=node,edges=edge,directed=TRUE)

    ## Set arrows
    ar <- arrow(angle=30,length=unit(5,"mm"),ends="last",type="closed")
    ## Plot
    ggraph(net,layout="graphopt") +
    ## Edges
    geom_edge_link(aes(start_cap=circle(log(node1.size)+2,unit="native"),
                       end_cap=circle(log(node2.size)+2,unit="native"),
                       width=weight,label=weight),
        position="identity",angle_calc="along",force_flip=TRUE,
        label_dodge=unit(4.0,"mm"),label_push=unit(-0.4,"mm")) +
        ## Width scale
        scale_edge_width(range=c(0.4,4),breaks=c(1:10),name="Movements\nbetween zones") +
    ## Add arrows separately
    geom_edge_link(arrow=ar,aes(start_cap=circle(log(node1.size)+1,unit="native"),
        end_cap=circle(log(node2.size)+1,unit="native"))) +
    ## Nodes
        ## Plot location id
        geom_node_label(aes(label=id,hjust=log(size+6),vjust=log(size+6)),repel=TRUE,
                        label.padding=unit(0.8,"mm"),label.r=unit(0.0,"mm"),label.size=0.1,size=3.5) +
        ## Circle
        geom_node_circle(aes(r=log(size)+1),color="black",fill="white",size=0.4) +
        ## Plot work activity
        geom_node_text(aes(size=w,hjust=log(w)+0.4),label="w",color="red",
                       position="identity",vjust=0.4,fontface="bold") +
        ## Plot school activity
        geom_node_text(aes(size=s,hjust=-log(s)-0.2),label="s",color="blue",
                       position="identity",vjust=0.4,fontface="bold") +
        ## Size scale
        scale_size(range=c(0,5),breaks=c(1:100),name="Numberof\nActivities",
                   guide=guide_legend(override.aes=list(label="a",color="black"))) +
        # scale_color() +
    ## Theme
    theme_graph() + coord_fixed()

这就是我想要的结果。

这是上述脚本的结果。

要达到我想要的结果，有两个与图例相关的问题：

• 如何用其他字体替换“活动数量”中重叠的“w”和“s”，例如黑色的“a”（活动），如所需结果所示？
  
• 如何添加所需结果中显示的另一手动图例“活动类型”？
  

虽然它写在ggraph，我想语法似乎与ggplot2。我很感激你的建议！

==========更新==========

第一个问题已通过更改解决scale_size参数如更新的脚本中所示。

然而，第二个问题仍然存在，我又发现了一个问题0-value符号位于圆圈中心（非常小的点）。我找到了一些解决方案来解决该问题，方法是应用 1)subset()省略0-value数据框中的记录data=subset(df,x!=0), 2) 只需用 NA 填充 0 值即可data=ifelse(x==0,NA,.)方法，但是正如它所写的那样graph对象，它可能不适用于这种情况。

========== 更新版本 2 ==========

这确实很棘手，但不知怎的，我可以删除线中心的点并添加一个图例。

我真的不确定原因，但前一个问题已通过 1) 替换解决0 values in node数据帧由NA, 2) 替换NA in aes(size=...)geom_node_text 中的语句为aes(size=ifelse(is.na(w),0,w) ...，然后 3) 指定颜色color=ifelse(w==0,"white","red")。它不会删除数据，只是改变颜色0-value变成白色，使其看不见。

我想这不是正式的解决方案，只是我在数十次试验中遇到的方式。有趣的是 1) 和 2) 应该结合起来，否则会返回错误。

因此，这是最终更新：

## Packages
    library(igraph)
    library(tidygraph)
    library(ggraph)
    library(ggplot2)
    library(tidyverse)

    ## Edge and node
    edge <- data.frame(from=c(0,0,0,0,1,2,3),
                       to=c(0,1,2,3,0,0,0),
                       weight=c(1,3,1,1,3,1,1))
    node <- data.frame(id=c(0,1,2,3),
                       p=c(9,1,0,0),
                       w=c(0,2,0,0),
                       s=c(0,1,1,1),
                       size=c(9,3,1,1),
                       gr=c(0,1,1,2))

    ## Load data frames as tbl_graph class
    edge <- edge %>% mutate(from=from+1,to=to+1)
    # THIS IS QUITE STRANGE OPERATION FOR CHANGING COLOR
    node <- node %>% mutate_at(vars(p,w,s,size),funs(ifelse(.==0,NA,.)))
    net <- tbl_graph(nodes=node,edges=edge,directed=TRUE)

## Set arrows
ar <- arrow(angle=30,length=unit(5,"mm"),ends="last",type="closed")
## Plot
ggraph(net,layout="graphopt") +
    ## Edges
    geom_edge_link(aes(start_cap=circle(log(node1.size)+2,unit="native"),
                       end_cap=circle(log(node2.size)+2,unit="native"),
                       width=weight,label=weight),
        position="identity",angle_calc="along",force_flip=TRUE,
        label_dodge=unit(4.0,"mm"),label_push=unit(-0.4,"mm")) +
        ## Width scale
        scale_edge_width(range=c(0.4,4),breaks=c(1:10),name="Movements\nbetween zones") +
    ## Add arrows separately
    geom_edge_link(arrow=ar,aes(start_cap=circle(log(node1.size)+1,unit="native"),
        end_cap=circle(log(node2.size)+1,unit="native"))) +
    ## Nodes
        ## Plot location id
        geom_node_label(aes(label=id,hjust=log(size+6),vjust=log(size+6)),repel=TRUE,
                        label.padding=unit(0.8,"mm"),label.r=unit(0.0,"mm"),label.size=0.1,size=3.5) +
        ## Circle
        geom_node_circle(aes(r=log(size)+1),color="black",fill="white",size=0.4) +
        ## Plot work activity: NOT KNOW WHY IT WORKS!!
        geom_node_text(aes(size=ifelse(is.na(w),0,w),hjust=log(w)+0.4,color=ifelse(w==0,"white","red")),label="w",
                       position="identity",vjust=0.4,fontface="bold") +
        ## Plot school activity
        geom_node_text(aes(size=ifelse(is.na(s),0,s),hjust=-log(s)-0.2,color=ifelse(s==0,"white","blue")),label="s",
                       position="identity",vjust=0.4,fontface="bold") +
        ## Edit legend
        scale_size_continuous(range=c(0,5),breaks=c(1:100),name="Numberof\nActivities",
                   guide=guide_legend(override.aes=list(label="a",color="black"))) +
        scale_color_manual(name="Type of Activity",guide=guide_legend(override.aes=list(label=c("w","s"))),
                           values=c("red","blue"),labels=c("Work","School")) +
    ## Theme
    theme_graph() + coord_fixed()

然而，由于它仍然是丑陋的代码，我仍在等待您的建议以进行更合适的操作。