如何在表达式(粘贴(斜体()中添加一个新的转义符来表示ggplot文本？

Question

我有个情节：

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如您所见，我已经应用c(expression(paste(italic("TERT"),"p-wt", "\nn = 504")), expression(paste(italic("TERT"),"-alt"))))对TERT标签文本进行斜体化。我需要向标签文本应用换行符(如\n中的换行符)。子序列标签文本n = 504不应该被斜体化，因此它看起来如下：

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您可以看到我在paste中的尝试是... "\nn = 504"。

怎么解决这个问题呢？

脚本

library(tidyverse)
ggplot(p, aes(time, P))  +
  geom_ribbon(aes(ymin = lower, ymax = upper, fill = CIF), alpha = 0.175) +
  geom_line(aes(color = CIF), size=.9) +
  scale_y_continuous(name="Absolute risk of recurrence-free death", breaks = seq(0,.30,.05), 
                     labels=c("0%", "5%", "10%", "15%", "20%", "25%", "30%")) +
  scale_x_continuous(name="Time in months", breaks = seq(0,84,6)) +
  coord_cartesian(xlim=c(0,84), ylim=c(0,.3)) +
  scale_color_manual(name = "",
                     values=c("#2C77BF", "#E38072"),
                     labels=c(expression(paste(italic("TERT"),"p-wt", "\nn = 504")), expression(paste(italic("TERT"),"-alt")))) + 
  scale_fill_manual(name = "", 
                    values = c("#2C77BF", "#E38072"),
                    labels=c(expression(paste(italic("TERT"),"p-wt","\nn = 504")), expression(paste(italic("TERT"),"-alt"))))

数据

p <- structure(list(CIF = c("CIF0 2; tert.mut=1", "CIF0 2; tert.mut=0", 
"CIF0 2; tert.mut=0", "CIF0 2; tert.mut=0", "CIF0 2; tert.mut=0", 
"CIF0 2; tert.mut=0", "CIF0 2; tert.mut=1", "CIF0 2; tert.mut=0", 
"CIF0 2; tert.mut=0", "CIF0 2; tert.mut=0", "CIF0 2; tert.mut=0", 
"CIF0 2; tert.mut=1", "CIF0 2; tert.mut=0", "CIF0 2; tert.mut=0", 
"CIF0 2; tert.mut=0", "CIF0 2; tert.mut=1", "CIF0 2; tert.mut=0", 
"CIF0 2; tert.mut=0", "CIF0 2; tert.mut=0", "CIF0 2; tert.mut=1", 
"CIF0 2; tert.mut=0", "CIF0 2; tert.mut=0", "CIF0 2; tert.mut=0", 
"CIF0 2; tert.mut=1", "CIF0 2; tert.mut=0"), P = c(0.107692307692308, 
0.0318799398246248, 0.104250176996486, 0.0318799398246248, 0.0638830432377014, 
0.0238177738177738, 0.0923076923076923, 0.0318799398246248, 0.0360585922036334, 
0.0996677826035525, 0.0996677826035525, 0.0615384615384615, 0.0382025715809015, 
0.0278199117586866, 0.0954782533502835, 0.143589743589744, 0.00595238095238095, 
0.0178571428571429, 0.0424905303354376, 0.0615384615384615, 0.0218253968253968, 
0.066596150754335, 0.044647744153306, 0.107692307692308, 0.0468049579711745
), time = c(21.37, 15, 131, 11.37, 51, 2.4, 20, 13, 16.89, 103, 
103, 3, 21, 6, 94, 82.8, 0.5, 1.233333333, 23, 1.56, 2.02, 58, 
24, 27.6, 25.96666667), var = c(0.00147837960855712, 6.15061126865662e-05, 
0.000249645579418861, 6.15061126865662e-05, 0.000128780021887127, 
4.61483225334451e-05, 0.00128903049613109, 6.15061126865662e-05, 
6.96689640374372e-05, 0.000231580946236407, 0.000231580946236407, 
0.000888484296768321, 7.39453689578964e-05, 5.37466343441789e-05, 
0.000216441563404178, 0.0019532358940643, 1.17399803836879e-05, 
3.47981454486557e-05, 8.24380449006048e-05, 0.000888484296768321, 
4.23592239658944e-05, 0.00013534809548244, 8.67087414414869e-05, 
0.00147837960855712, 9.09589688896577e-05), lower = c(0.0528514417396508, 
0.0196518457186032, 0.0772750945993973, 0.0196518457186032, 0.045016193151503, 
0.0135965306863706, 0.0425647784155885, 0.0196518457186032, 0.0228690129108758, 
0.0737220048215361, 0.0737220048215361, 0.0235520073396644, 0.0245335443794, 
0.016570605417229, 0.070434217792914, 0.0775445493926726, 0.00192365089076652, 
0.00933140136537858, 0.027903654874056, 0.0235520073396644, 0.0121462452612258, 
0.047198554448097, 0.0296158713071857, 0.0528514417396508, 0.0313396074133714
), upper = c(0.212668574724397, 0.0515142923656493, 0.139902848146699, 
0.0515142923656493, 0.0902751063867387, 0.041559299113097, 0.193977353098234, 
0.0515142923656493, 0.0566316095215483, 0.134062034000531, 0.134062034000531, 
0.155705170149612, 0.0592526431191566, 0.0465232824968026, 0.128790443953785, 
0.257453579417542, 0.0183406721597764, 0.0340375487466844, 0.0644459736704804, 
0.155705170149612, 0.0390636938444939, 0.093565227984076, 0.0670412417437027, 
0.212668574724397, 0.0696230518381585), n.risk = c(23, 378, 36, 
412, 194, 478, 24, 395, 363, 74, 74, 56, 336, 453, 100, 3, 499, 
491, 330, 58, 481, 177, 324, 17, 309), n.event = c(1, 0, 0, 0, 
1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0
)), row.names = c(NA, -25L), class = c("data.table", "data.frame"
))

Answer 1

使用atop将文本放在其他文本之上。见?plotmath。

ggplot(p, aes(time, P))  +
  geom_ribbon(aes(ymin = lower, ymax = upper, fill = CIF), alpha = 0.175) +
  geom_line(aes(color = CIF), size=.9) +
  scale_y_continuous(name="Absolute risk of recurrence-free death", breaks = seq(0,.30,.05), 
                     labels=c("0%", "5%", "10%", "15%", "20%", "25%", "30%")) +
  scale_x_continuous(name="Time in months", breaks = seq(0,84,6)) +
  coord_cartesian(xlim=c(0,84), ylim=c(0,.3)) +
  scale_color_manual(name = "",
                     values=c("#2C77BF", "#E38072"),
                     labels=c(expression(atop(paste(italic("TERT"),"p-wt"), "n = 504")), expression(paste(italic("TERT"),"-alt")))) + 
  scale_fill_manual(name = "", 
                    values = c("#2C77BF", "#E38072"),
                    labels=c(expression(atop(paste(italic("TERT"),"p-wt"),"\nn = 504")), expression(paste(italic("TERT"),"-alt"))))