在上一个问题中,我用ggplot2代替了(使用字段包)生成的等高线图(下面的完整示例).唯一的麻烦是,我想复制轮廓标签的位置,contour()默认情况下是在线的"最平坦"部分 - 第二张图片可能会显示原因.我对如何设置计算感到困惑.我在这里看到可以抓取用于生成轮廓线的数据,然后geom_text()可以用来绘制文本.那么剩下的就是弄清楚如何计算"最平坦"的部分.想法？
library(fields)
library(ggplot2)
library(reshape)
library(directlabels)
sumframe<-structure(list(Morph = c("LW", "LW", "LW", "LW", "LW", "LW", "LW", "LW", "LW", "LW", "LW", "LW", "LW", "SW", "SW", "SW", "SW", "SW", "SW", "SW", "SW", "SW", "SW", "SW", "SW", "SW"), xvalue = c(4, 8, 9, 9.75, 13, 14, 16.25, 17.25, 18, 23, 27, 28, 28.75, 4, 8, 9, 9.75, 13, 14, 16.25, 17.25, 18, 23, 27, 28, 28.75), yvalue = c(17, 34, 12, 21.75, 29, 7, 36.25, …