单独移动元素并更改 ggdist 中的 y 轴比例

Question

我当前的绘图如下所示。

它的代码是这样的：

ggplot(data, aes(x = factor(Class), y = dry_r45, group = 1)) + 
  stat_slabinterval(aes(y = dry_r45), interval_color = NA, fill = NA, slab_linewidth = 0.7, slab_color = "#DDCC77", point_color = "#DDCC77") +
  stat_slabinterval(aes(y = mddl_45), interval_color = NA, fill = NA, slab_linewidth = 0.7, slab_color = "#44AA99", point_color = "#44AA99") +
  stat_slabinterval(aes(y = wt_rc45), interval_color = NA, fill = NA, slab_linewidth = 0.7, slab_color = "#CC6677", point_color = "#CC6677") +
  labs(title = "Density plot for drought exposure, mddl, and wt by Class") +
  theme_minimal() +
  facet_wrap(~ Class, nrow = 2,scales="free") +coord_flip() +ylim(0,1000)

这一切都很棒，但我想摆脱每个子图下方的所有空白空间（负 Y 空间），并确保线条不会与点碰撞（因此将线条向上移动少量）。 我不知道如何做到这一点，以便删除 y 轴中的“负空间”，而且我似乎也无法单独移动点或线，因为我认为它们是从同一个 stat_slabinterval 参数中调用的.

一些示例数据：

structure(list(Class = structure(c(1L, 1L, 3L, 3L, 3L, 3L, 3L, 
3L, 3L, 1L, 1L, 3L, 3L, 1L, 1L, 1L, 1L, 1L, 3L, 3L, 3L, 3L, 3L, 
3L, 3L, 3L, 3L, 3L, 3L, 4L, 3L, 4L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 
3L, 3L, 3L, 3L, 3L, 3L, 4L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 
3L, 4L, 1L, 1L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 
3L, 3L, 4L, 3L), levels = c("AMPHIBIA", "AVES", "MAMMALIA", "REPTILIA"
), class = "factor"), dry_r45 = c(363.388145949796, 131.155995859126, 
392.051280340233, 582.12436836741, 633.665139548256, 183.849416151781, 
122.220776927914, 123.221302688033, 664.803469572132, 282.41950446681, 
428.865496826172, 638.74445964881, 573.595947613427, 736.178894042969, 
631.199749226331, 865.028329673332, 184.875174569854, 592.06201171875, 
424.021702785801, 406.961345310191, 957.064789292682, 288.912997795784, 
334.388577027565, 624.237691191004, 566.094641214125, 965.949048973318, 
1086.51134631976, 818.705607823815, 812.030196080853, 418.2314861611, 
930.134145798456, 355.866535987484, 684.294302829476, 556.960110937029, 
398.931482238751, 752.938455770096, 462.381468014355, 398.031650214026, 
298.475676238082, 404.424822059044, 256.658201651774, 596.230151226608, 
729.547485581456, 625.906604886473, 1013.6908622825, 276.346704896106, 
410.053284821958, 541.667721972739, 681.618416008016, 795.054924532415, 
846.914624371795, 1015.57506061187, 611.549468843312, 607.54233085132, 
214.093516755057, 387.734687936783, 847.17546192728, 331.378194899786, 
73.4170806285058, 951.697522815941, 408.532844147008, 412.570369907525, 
281.967407737638, 657.175493623395, 279.812453602327, 244.635951289973, 
872.925850282055, 1261.37923860897, 1235.22716577741, 697.819079558861, 
410.057326599648, 418.804483814327, 837.981430449478, 149.541834271081, 
264.866667957967), mddl_45 = c(230.500439431837, 163.710847456737, 
299.96951929863, 423.873927877018, 440.698367818376, 136.399273290044, 
152.50591804705, 214.297180644848, 722.051286387759, 274.571592029772, 
262.856053161621, 357.064670976097, 295.897055939346, 351.93798828125, 
708.99732498796, 667.473720823298, 117.744196577975, 496.816101074219, 
373.646014965177, 419.876292813853, 747.141463729431, 249.665116104439, 
364.860711117477, 444.033146888809, 535.850235853449, 710.513437306163, 
827.295865526503, 653.396152980815, 757.848262892133, 507.858365499264, 
743.698141956148, 370.792797109154, 288.362213316226, 479.384836448459, 
446.564511233827, 772.255513162575, 517.041371310898, 308.440145695875, 
374.333019052753, 322.049826190655, 304.716008620463, 710.442666526399, 
592.912785708139, 428.822896338398, 710.029178335925, 619.404727700808, 
415.426429585988, 408.516053370282, 413.470117480482, 637.426605185107, 
576.462000244721, 815.561222733534, 716.702217131378, 778.149816356721, 
398.577447637592, 324.873910004304, 628.970334656669, 106.597244141594, 
208.704991215036, 643.954423847175, 417.634095213485, 416.941213162062, 
443.085707354952, 727.496359936908, 344.487907053418, 329.172377352853, 
621.26261704873, 789.666201080418, 824.791253843076, 736.890392529379, 
415.414993990779, 411.323582996079, 639.800383809321, 222.484497747311, 
242.336969253859), wt_rc45 = c(76.3325505422698, 26.0749306037862, 
213.660518472799, 223.602243746736, 260.973150763789, 99.5864348594492, 
69.4877840233901, -0.007544409787213, 165.824787692528, 201.850371611746, 
268.678361129761, 179.384988762923, 300.252028279575, 643.518493652344, 
70.0349630538731, 313.892097528487, 62.9863443202421, 551.368432617188, 
138.110343445225, 127.724954321858, 309.662423873126, 73.4286095145551, 
89.386721275755, 402.7680647483, 178.621465983978, 292.085215506391, 
317.640496352263, 345.16239351255, 495.180555146173, 272.436864661596, 
319.123857185159, 90.7415581058763, 246.418129166891, 201.391396672138, 
113.457046621468, 227.448114313626, 198.105969728023, 220.517736183205, 
99.8547521656706, 235.885256335919, 138.281499654164, 194.346132279175, 
461.937739263605, 244.087637602723, 272.772766122321, -17.0701460841088, 
136.625117421999, 213.479783690862, 265.529688418323, 284.292623990206, 
236.246770851961, 352.069942762743, 186.821549232814, 113.429620774066, 
19.0431269788363, 235.247781032165, 297.818652483379, 67.7614093356662, 
28.8775403752636, 205.488691354048, 134.06130174424, 137.646887953974, 
66.2057470847847, 176.012013026833, 56.2544402972126, 37.3199555074739, 
146.257366275971, 245.445828631319, 239.06573905842, 150.303573937585, 
136.63193962908, 142.41180761378, 331.730189780207, 70.0905639991735, 
93.7739139260316)), row.names = c(NA, 75L), class = "data.frame")

Answer 1

首先，我会注意到，我已经交换了您的

x

和

y

美学映射并删除了

coord_flip()

，因为这是等效的，但（在我看来）更容易推理。

我还用

+ xlim(0, 1000)

替换了（本来应该是的）

+ coord_cartesian(xlim = c(0, 1000))

，因为通常不推荐前者。

xlim()

和

ylim()

删除数据而不是简单地更改可见限制，这将更改汇总统计的结果（事实上，我收到了有关示例数据集中丢失数据的警告）。

关于您的具体问题...

去除轴空间

轴空间是通过将一个因子映射到

y

轴上而创建的。默认情况下，ggplot2 在

x

/

y

轴的边缘放置相当大的间距，并将因子映射到它们上，当您的因子具有多个级别但可能只有一个或两个级别时，这种方法效果很好。您可以通过将

expansion()

值传递给相应

expand

函数的

scale_...

参数来控制它。

例如：

ggplot(data, aes(y = factor(Class), x = dry_r45, group = 1)) + 
  stat_slabinterval(aes(x = dry_r45), interval_color = NA, fill = NA, slab_linewidth = 0.7, slab_color = "#DDCC77", point_color = "#DDCC77") +
  stat_slabinterval(aes(x = mddl_45), interval_color = NA, fill = NA, slab_linewidth = 0.7, slab_color = "#44AA99", point_color = "#44AA99") +
  stat_slabinterval(aes(x = wt_rc45), interval_color = NA, fill = NA, slab_linewidth = 0.7, slab_color = "#CC6677", point_color = "#CC6677") +
  labs(title = "Density plot for drought exposure, mddl, and wt by Class") +
  theme_minimal() +
  facet_wrap(~ Class, nrow = 2,scales="free") +
  coord_cartesian(xlim = c(0,1000)) +
  # add a smaller-than-default expansion amount at the scale edge
  scale_y_discrete(expand = expansion(add = 0.1))

与板分离点

要将点与板分开，您始终可以使用

stat_slab() + stat_pointinterval()

来替代

stat_slabinterval()

。

但是，使用当前代码执行此操作将导致在绘图中添加六个层，每个层都具有非常相似的设置。我希望避免代码重复，因此我首先将数据转换为长格式，以便我们可以将不同的变量映射到

color

美学上。除了节省代码重复之外，这还允许我们添加图例。

我还将

y

变量设置为空白值，因为它对于分面标题来说是多余的：

data |>
  # this will give a `name` column with "dry_r45", "mddl_45",
  # and "wt_rc45" and a corresponding `value` column
  tidyr::pivot_longer(c(dry_r45, mddl_45, wt_rc45)) |>
  ggplot(aes(y = "", x = value)) + 
  stat_slab(aes(color = name), fill = NA, linewidth = 0.7) +
  # .width = 0 suppresses the interval and height = 0 ensures
  # extra blank space above/below the pointinterval is not added
  stat_pointinterval(aes(color = name), .width = 0, height = 0) +
  labs(title = "Density plot for drought exposure, mddl, and wt by Class") +
  theme_minimal() +
  facet_wrap(~ Class, nrow = 2,scales="free") +
  coord_cartesian(xlim = c(0,1000)) +
  scale_y_discrete(expand = expansion(add = 0.1)) +
  # instead of repeatedly specifying colors in separate layers
  # we used aes(color = name) above and specify the colors here
  scale_color_manual(values = c(dry_r45 = "#DDCC77", mddl_45 = "#44AA99", wt_rc45 = "#CC6677"))

从这里开始，您应该能够（例如）向

position = position_nudge(y = -0.1)

或

stat_pointinterval()

层添加类似

stat_slab()

的内容，以将其与其他层分开向上或向下移动。