“`ggplot2` 2”图例未显示添加系列的标签

Question

在以下两个系列的ggplot2 (美国国内生产总值及其移动平均值)中，图例没有显示移动平均序列：

require(xts);require(data.table);require(ggplot2);require(ggthemes)

# US GDP quarterly data
data <- structure(list(ShortName = c("US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)","US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)",  "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)",  "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)","US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)",  "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)","US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)", "US GDP QoQ (Annualised)"), Date = structure(c(10681L, 10772L,10864L, 10956L, 11047L, 11138L, 11230L, 11322L, 11412L, 11503L,11595L, 11687L, 11777L, 11868L, 11960L, 12052L, 12142L, 12233L,12325L, 12417L, 12508L, 12599L, 12691L, 12783L, 12873L, 12964L,13056L, 13148L, 13238L, 13329L, 13421L, 13513L, 13603L, 13694L,13786L, 13878L, 13969L, 14060L, 14152L, 14244L, 14334L, 14425L,14517L, 14609L, 14699L, 14790L, 14882L, 14974L, 15064L, 15155L,15247L, 15339L, 15430L, 15521L, 15613L, 15705L, 15795L, 15886L,15978L, 16070L), class = c("IDate", "Date")), Value = c(3.8,3.4, 5.2, 7.1, 1.2, 7.8, 0.5, 2.1, -1.1, 2.1, -1.2, 1, 3.8, 2.2,1.9, 0.2, 2, 3.8, 6.9, 4.6, 2.4, 3.1, 3.6, 3.4, 4.5, 2.2, 3.3,2.2, 4.9, 1.3, 0.3, 3.2, 0.3, 3.1, 2.7, 1.5, -2.7, 2, -2, -8.3,-5.4, -0.4, 1.3, 3.9, 1.6, 3.9, 2.8, 2.8, -1.3, 3.2, 1.4, 4.9,3.7, 1.2, 2.8, 0.1, 1.1, 2.5, 4.1, 2.4)), .Names = c("ShortName","Date", "Value"), class = c("data.table", "data.frame"), row.names = c(NA,-60L))

ggplot(data, aes_string(x="Date", y="Value", colour="ShortName")) + 
  geom_line(size=1.2) +

  # add 4 quarter moving average series
  geom_line(aes(x=Date, 
                y=rollmean(Value, k=4, fill=NA, align="right"))
            , colour="red") +

  # the economist theme from package::ggthemes
  theme_economist_white(gray_bg=FALSE) + 
  scale_colour_economist() +
  xlab("") + ylab("")

问题：如何将移动平均线系列标签添加到图例中(文本中说“4季度移动avg"？)

的额外问题：如何从图例中删除ShortName文本？

Answer 1

也许把某些东西指定为美学

ggplot(data) + 
  geom_line(aes_string(x="Date", y="Value", colour="ShortName"), size=1.2) +
  # add 4 quarter moving average series
  geom_line(aes(x=Date, 
                y=rollmean(Value, k=4, fill=NA, align="right"),
                linetype =  'Moving average'),
            colour="red") +
  scale_colour_manual('', values = "blue") +
  scale_linetype_manual('', values = 1)

和and主题

ggplot(data) + 
  geom_line(aes_string(x="Date", y="Value", colour="ShortName"), size=1.2) +
  # add 4 quarter moving average series
  geom_line(aes(x=Date, 
                y=rollmean(Value, k=4, fill=NA, align="right"),
                linetype =  'Moving average'),
            colour="red") +
  scale_colour_economist(name='') +
  #scale_colour_manual('', values = "blue") +
  scale_linetype_manual('', values = 1) +
  theme_economist_white(gray_bg=FALSE)

​

​

您可以更改图例项的顺序。

plot <- ggplot(data) + 
  geom_line(aes_string(x="Date", y="Value", colour="ShortName"), size=1.2) +
  # add 4 quarter moving average series
  geom_line(aes(x=Date, 
                y=rollmean(Value, k=4, fill=NA, align="right"),
                linetype =  'Moving average'),
            colour="red") +
  scale_colour_economist(name='') +
  #scale_colour_manual('', values = "blue") +
  scale_linetype_manual('', values = 1) +
  theme_economist_white(gray_bg=FALSE)

plot + guides(colour = guide_legend(order = 1), 
              linetype = guide_legend(order = 2))

​

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