Question

我得到了以下数据集：

 Name     Year-Month     Value
 A         2002-01        -3.45
 A         2003-02         2.87
 A         2004-05         1.78
 A         2005-01        -9.54
 B         2000-01        -1.45
 B         2001-02         10.87
 B         2002-01         5.78
 C         2004-01        -6.45
 C         2005-01         4.87

我想要做的是我想以特殊方式绘制值。在x轴上应该有几年和几个月，但是由于2000年至2008年期间有许多年和月的观察，我只想写出一年中的第一个和第六个月以及一年中所有其他月份都是只是标志着。

对于所有观察，我想将值分散为点或十字，而不管它们是哪个字母。

我画了一张照片。

这张照片只是一个片段。在实际情节中，价值必须在年月的线上激动。

使用ggplot2或任何其他软件包是否可以轻松实现此目的？

Answer 1

为了每6个月显示一次x轴标签，同时每月显示次要标记，我们需要一个小技巧：每个月制作一个主要的标记，但每6个月只显示标签。

要使用scale_x_date，需要从Date创建“假”Year-Month列。在这里，我只是将该月的第一天01附加到现有的Year-Month列。

library(magrittr)
library(tidyverse)

df <- read.table(text = "Name     Year-Month     Value
 A         2002-01        -3.45
 A         2003-02         2.87
 A         2004-05         1.78
 A         2005-01        -9.54
 B         2000-01        -1.45
 B         2001-02         10.87
 B         2002-01         5.78
 C         2004-01        -6.45
 C         2005-01         4.87",
                 header = TRUE)

# Create a Date column so that scale_x_date can be used
df %<>% 
  as.tibble() %>% 
  mutate(Date = as.Date(paste0(Year.Month, "-01")))
df

#> # A tibble: 9 x 4
#>   Name  Year.Month  Value Date      
#>   <fct> <fct>       <dbl> <date>    
#> 1 A     2002-01     -3.45 2002-01-01
#> 2 A     2003-02      2.87 2003-02-01
#> 3 A     2004-05      1.78 2004-05-01
#> 4 A     2005-01     -9.54 2005-01-01
#> 5 B     2000-01     -1.45 2000-01-01
#> 6 B     2001-02     10.9  2001-02-01
#> 7 B     2002-01      5.78 2002-01-01
#> 8 C     2004-01     -6.45 2004-01-01
#> 9 C     2005-01      4.87 2005-01-01

# Auto x-axis break
ggplot(df, aes(x = Date, y = Value)) +
  geom_point(pch = 4, size = 5) +
  scale_x_date(expand = c(0.015, 0.015),
               breaks = scales::pretty_breaks(), date_labels = "%Y-%b") +
  theme_bw()

# Break every 6 months
ggplot(df, aes(x = Date, y = Value)) +
  geom_point(pch = 4, size = 5) +
  scale_x_date(expand = c(0.015, 0.015),
               date_breaks = "6 months", date_labels = "%Y-%b") +
  theme_bw()

# Color by Name, manually setup date range
ggplot(df, aes(x = Date, y = Value, color = Name)) +
  geom_point(pch = 4, size = 5) +
  scale_x_date(expand = c(0.015, 0.015),
               breaks = seq(min(df$Date), max(df$Date), by = "6 months"), 
               date_minor_breaks = "1 month",
               date_labels = "%Y-%b") +
  theme_bw()

# Add minor tick
# Trick: make major ticks for every month but only show labels every 6 months
labels_month = format(seq(from = min(df$Date), to = max(df$Date), by = "1 months"), 
                      "%Y-%b")
labels_month[rep(c(FALSE, TRUE), c(1, 4))] <- ""
labels_month
#>  [1] "2000-Jan" ""         ""         ""         ""         "2000-Jun"
#>  [7] ""         ""         ""         ""         "2000-Nov" ""        
#> [13] ""         ""         ""         "2001-Apr" ""         ""        
#> [19] ""         ""         "2001-Sep" ""         ""         ""        
#> [25] ""         "2002-Feb" ""         ""         ""         ""        
#> [31] "2002-Jul" ""         ""         ""         ""         "2002-Dec"
#> [37] ""         ""         ""         ""         "2003-May" ""        
#> [43] ""         ""         ""         "2003-Oct" ""         ""        
#> [49] ""         ""         "2004-Mar" ""         ""         ""        
#> [55] ""         "2004-Aug" ""         ""         ""         ""        
#> [61] "2005-Jan"

x_breaks = seq(min(df$Date), max(df$Date), by = "1 months")

ggplot(df, aes(x = Date, y = Value, color = Name)) +
  geom_point(pch = 4, size = 5) +
  scale_x_date(expand = c(0.015, 0.015),
               labels = labels_month, 
               breaks = x_breaks) +
  theme_classic() +
  theme(axis.text.x = element_text(angle = 90, vjust = 0.5))

由reprex package（v0.2.0）创建于2018-06-05。

使用ggplot散射点

1 个答案: