填写图例，ggplot的符号

如何解决填写图例，ggplot的符号

大家好，谢谢，

我试图让图例显示填充的形状，而不是简单地用颜色勾勒出轮廓（如下所示）：

我的代码如下：

    p.ch4 <- ggplot(ch4.data,aes(x=date,y=value,group = type,fill=type,color=type)) +
  geom_line() +
  geom_point(aes(shape=type),color = "black",size =4) +
  geom_point(aes(shape=type,color=type),size=3) +
  scale_shape_manual(values = c(21:24)) +
  scale_fill_manual(values = c("darkorchid3","indianred3","dodgerblue3")) +
  scale_color_manual(values = c("darkorchid3","dodgerblue3")) +
  annotate("rect",xmin=as.POSIXct("2017-11-09"),xmax=as.POSIXct("2018-04-09"),ymin=0,ymax=75,alpha=.25) +
  scale_y_continuous(sec.axis = sec_axis(~.,name = expression(paste('Methane (',mu,'M)')))) +
  labs(y = expression(paste('Methane (','M)')),x = "",color = "",shape = "") +
  theme_linedraw(base_size = 18) +
  #theme(legend.position = "none") +
  theme(panel.grid.major = element_blank(),panel.grid.minor = element_blank(),strip.text = element_text(face = "bold")) +
  theme(axis.text = element_text(angle = 45,hjust = 1))

print(p.ch4)

我意识到我在数据点颜色，轮廓和形状方面做了很多工作，我想知道我的问题是否在其中？

为了可重复性，这是我的数据集“ ch4.data”：

> dput(ch4.data)
structure(list(type = structure(c(1L,1L,2L,3L,3L),.Label = c("SWI","4cm","12cm"),class = "factor"),date = structure(c(1537167600,1535266800,1533279600,1531292400,1529305200,1527318000,1526713200,1527231600,1525762800,1524294000,1522825200,1521356400,1516089600,1511596800,1509606000,1537340400,1534575600,1531119600,1530255600,1527663600,1525071600,1517212800,1513756800,1510300800,1537167600,1535094000,1533020400,1530946800,1528873200,1528441200,1524898800,1522393200,1519545600,1516435200,1514361600,1510992000
),class = c("POSIXct","POSIXt"),tzone = ""),value = c(52.43,40.37,12.92,5.12,4.93,2.4,1.97,3.07,5.7,3.56,2.74,0.67,0.78,0.48,0.7,0.3,0.21,4.11,1.54,4.86,7.42,3.62,0.81,0.37,6.2,9.14,34.11,57.83,63.02,63.56,54.13,42.92,32.59,23.23,9.97,5.62,0.52),geochem = c("ch4","ch4","ch4")),row.names = c(NA,-37L),class = "data.frame")

谢谢！

解决方法

可以这样实现。重要的步骤是为所有三个音阶赋予相同的名称，以便将图例合并为一个：

顺便说一句：我还放下了第二个geom_point层，只是添加了黑色作为参数。

编辑：正如@ chemdork123在他的评论中正确指出的，通过在labs()语句中为所有三个比例设置相同的标签或删除空白，即{{ 1 {}和""标度的标签。

color

^{由reprex package（v0.3.0）于2020-08-24创建}