如何在ggplot2中绘制一个不错的箭头

本文介绍了如何在ggplot2中绘制一个不错的箭头的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 我正在创建一个 ggplot 图表，我希望在两点之间有一些箭头。主要任务可以通过 geom_line（arrow = arrow（））轻松完成。但是，我想要一些漂亮的粗箭头。通过 size = 调整箭头的大小并没有帮助，因为它会彻底弄乱箭头。我举例说明了我的问题： 创建一些示例数据和一个图： VALUE DATA ggplot（DATA，aes（x = VALUE，y = NAME））+ geom_point（size = 5，aes（color = YEAR））+ geom_line（arrow = arrow（length = unit（0.30，cm），ends =first，type =closed）） 结果图如下所示： 现在我试着加厚箭头...... ggplot（DATA，aes（x = VALUE，y = NAME））+ geom_point（size = 5，aes（color = YEAR））+ geom_line（arrow = arrow（length = unit（0.30，cm），ends =first，type =closed），size = 3） pre> 结果如下所示： 我的问题：有什么办法可以绘制一些漂亮的粗箭头吗？ 我通常使用 geom_segment 创建箭头。但要做到这一点，我们需要修改数据从长到宽格式（通常在中使用 dcast > reshape2 或 data.table 包）。但是这次我尝试使用 base 的 reshape 函数。 ggplot（DATA，aes（x = VALUE，y = NAME））+ geom_point（size = 5，aes（color = YEAR））+ geom_segment（data = reshape（DATA，v.names =VALUE，idvar =NAME，timevar =YEAR，direction =wide）， aes（x = VALUE.2011，xend = VALUE .2016，y = NAME，yend = NAME），size = 2， arrow = arrow（length = unit（0.5，cm））） 编辑：I刚发现同样的问题属于封闭型箭头。现在，尝试将图保存为矢量图（pdf或svg，使用 ggsave 或绘图选项卡中的导出菜单）。结果并不杂乱。 I am creating a ggplot chart where I want to have some arrows between two points. The main task is easily done with geom_line(arrow = arrow()). However, I want to have some "beautiful" thick arrows. Resizing the arrow via size= doesn't help since it messes up the head of the arrow completely. I illustrate my Problems:Create some sample data and a plot: NAME <- c("A", "A", "B", "B", "C", "C") YEAR <- c(2016, 2011, 2016, 2011, 2016, 2011) YEAR <- as.factor(YEAR) VALUE <- c(1, 4, 1, 5, 2, 8) DATA <- data.frame(NAME, YEAR, VALUE)ggplot(DATA, aes(x=VALUE, y=NAME)) + geom_point(size=5, aes(colour=YEAR)) + geom_line(arrow = arrow(length=unit(0.30,"cm"), ends="first", type = "closed"))The resulting plot looks like that:Now I've tried to "thicken" the arrows...ggplot(DATA, aes(x=VALUE, y=NAME)) + geom_point(size=5, aes(colour=YEAR)) + geom_line(arrow = arrow(length=unit(0.30,"cm"), ends="first", type = "closed"), size = 3)That's the result shown here:My question: Is there any way to plot some "beautiful" thick arrows? 解决方案 I usually use geom_segment to create arrow. But to do that we need to modify the data from "long" to "wide" format (usually using dcast from reshape2 or data.table package). But this time I tried using base's reshape function.ggplot(DATA, aes(x=VALUE, y=NAME)) + geom_point(size=5, aes(colour=YEAR)) + geom_segment(data = reshape(DATA, v.names="VALUE", idvar = "NAME", timevar = "YEAR", direction = "wide"), aes(x=VALUE.2011, xend=VALUE.2016, y=NAME, yend=NAME), size = 2, arrow = arrow(length = unit(0.5, "cm")))EDIT: I just found that same issue pertains for "closed" type arrows. For now, try to save the plot as a vector graph (pdf or svg, using ggsave or Export menu in Plots tab). The result is not "messy". 这篇关于如何在ggplot2中绘制一个不错的箭头的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！