如何去除R语言swimplot包泳道图图例符号的边框？

要在保留图例线条/符号的前提下去除边框，只需在guide_legend的override.aes参数中添加stroke = NA，或指定图例符号为纯线条样式即可。

修改后的代码如下：

swimmer_lines(
  df_lines = resp, id = "study_id", start = "response_start",
  end = "response_end", name_col = "response", size = 1
) +
  scale_color_manual(
    name = "Response",
    values = c("PD" = "red", "SD" = "grey", "PR" = "mediumpurple", "CR" = "violetred1"),
    breaks = c("PD", "SD", "PR", "CR")
  ) +
  guides(color = guide_legend(
    override.aes = list(fill = NA, stroke = NA) # 添加stroke=NA去除边框
  ))

如果上述方法效果不佳，还可以直接指定图例符号为线条类型，彻底规避边框问题：

swimmer_lines(
  df_lines = resp, id = "study_id", start = "response_start",
  end = "response_end", name_col = "response", size = 1
) +
  scale_color_manual(
    name = "Response",
    values = c("PD" = "red", "SD" = "grey", "PR" = "mediumpurple", "CR" = "violetred1"),
    breaks = c("PD", "SD", "PR", "CR")
  ) +
  guides(color = guide_legend(
    override.aes = list(fill = NA),
    key_glyph = draw_key_path # 指定图例符号为纯线条样式
  ))

原理说明 #

• stroke = NA会直接取消图例符号的边框描边，配合已设置的fill=NA，最终仅保留线条样式
• draw_key_path是ggplot2内置的线条型图例绘制函数，能让图例直接显示为纯线条，从根源避免边框出现

内容的提问来源于stack exchange，提问作者Alex