Plotly R设置标记大小导致拟合线意外显示标记的问题

使用Plotly 4.10.2、R 4.3.1、RStudio 2023.06.1 Build 524制作包含散点集和最佳拟合线的双轨迹散点图时，遇到以下问题：

• 拟合线轨迹已设置mode="lines"，仅需显示线条，但为散点轨迹添加marker = list(size = 10)调整标记大小后，拟合线也出现了标记。
• 尝试改用两次add_trace语句分别创建两个轨迹，问题依旧。
  请问这是Bug吗？

相关数据：

# dt$d50
c(2.191258065, 4.371259836, 4.163834921, 4.299901482, 0.721296517, 
0.806656288, 0.838300519, 2.123984458, 1.281270095, 1.271034705, 
1.126324259, 2.158535202, 0.811873646, 0.997379781, 0.791658847, 
0.865206465, 1.697433187, 1.306820106, 1.002612879, 0.932092299, 
1.741705726, 1.546688167, 1.408641227, 0.922844563, 0.845056924, 
0.997727831, 1.102327201, 1.120945941, 1.092093241, 1.182791188, 
1.303034055, 1.200149608, 1.051766949, 0.917999368, 0.879761687, 
0.25661637, 0.367374289, 0.451367428, 0.594794813, 0.412664784, 
0.326505198, 0.343620551, 0.441396171, 0.475386025, 0.400242695, 
0.374735446, 0.386719965, 0.312585107, 3.261716671, 3.292011578, 
0.767037605, 1.651888689, 1.193666161, 1.934104802, 2.286671289, 
1.43194983, 1.611017108)

# dt$r501b3grange1
c(1.09698951244354, 3.16094923019409, 2.79072117805481, 3.07730960845947, 
0.744107246398926, 1.22431325912476, 1.53918492794037, 1.52391850948334, 
0.751307666301727, 0.827914595603943, 1.34772574901581, 1.02658534049988, 
0.776823580265045, 0.762321770191193, 1.20416533946991, 0.986024975776672, 
1.5238938331604, 1.06575691699982, 1.04620349407196, 1.24733889102936, 
0.65419340133667, 0.705933749675751, 0.824617326259613, 0.979621589183807, 
1.15843141078949, 0.93364292383194, 0.818296492099762, 0.993945062160492, 
0.955138683319092, 0.853289723396301, 0.850569367408752, 0.850764274597168, 
0.663198113441467, 0.516988277435303, 0.539037942886353, 0.751503467559814, 
0.677738070487976, 0.792271614074707, 0.792271614074707, 0.627113521099091, 
0.584987282752991, 0.684955239295959, 0.77651035785675, 0.729957222938538, 
0.848376214504242, 0.74308979511261, 0.549346268177032, 0.6502605676651, 
2.18274283409119, 2.94228267669678, 0.680980920791626, 1.51205325126648, 
0.92967689037323, 1.24754667282104, 1.08400869369507, 0.809762358665466, 
0.843399584293365)

这不是Bug，是Plotly的全局属性继承导致的问题。当你在散点轨迹中设置marker属性后，后续的轨迹会默认继承这些样式，即使设置了mode="lines"，Plotly仍然会应用继承的marker样式，导致拟合线出现标记。

解决方法很简单：在拟合线的add_trace中显式设置marker = list(opacity = 0)或者marker = NULL，覆盖继承的标记样式，确保拟合线只显示线条。

以下是完整的可运行代码示例：

library(plotly)

# 加载数据
d50 <- c(2.191258065, 4.371259836, 4.163834921, 4.299901482, 0.721296517, 
         0.806656288, 0.838300519, 2.123984458, 1.281270095, 1.271034705, 
         1.126324259, 2.158535202, 0.811873646, 0.997379781, 0.791658847, 
         0.865206465, 1.697433187, 1.306820106, 1.002612879, 0.932092299, 
         1.741705726, 1.546688167, 1.408641227, 0.922844563, 0.845056924, 
         0.997727831, 1.102327201, 1.120945941, 1.092093241, 1.182791188, 
         1.303034055, 1.200149608, 1.051766949, 0.917999368, 0.879761687, 
         0.25661637, 0.367374289, 0.451367428, 0.594794813, 0.412664784, 
         0.326505198, 0.343620551, 0.441396171, 0.475386025, 0.400242695, 
         0.374735446, 0.386719965, 0.312585107, 3.261716671, 3.292011578, 
         0.767037605, 1.651888689, 1.193666161, 1.934104802, 2.286671289, 
         1.43194983, 1.611017108)

r501b3grange1 <- c(1.09698951244354, 3.16094923019409, 2.79072117805481, 3.07730960845947, 
                   0.744107246398926, 1.22431325912476, 1.53918492794037, 1.52391850948334, 
                   0.751307666301727, 0.827914595603943, 1.34772574901581, 1.02658534049988, 
                   0.776823580265045, 0.762321770191193, 1.20416533946991, 0.986024975776672, 
                   1.5238938331604, 1.06575691699982, 1.04620349407196, 1.24733889102936, 
                   0.65419340133667, 0.705933749675751, 0.824617326259613, 0.979621589183807, 
                   1.15843141078949, 0.93364292383194, 0.818296492099762, 0.993945062160492, 
                   0.955138683319092, 0.853289723396301, 0.850569367408752, 0.850764274597168, 
                   0.663198113441467, 0.516988277435303, 0.539037942886353, 0.751503467559814, 
                   0.677738070487976, 0.792271614074707, 0.792271614074707, 0.627113521099091, 
                   0.584987282752991, 0.684955239295959, 0.77651035785675, 0.729957222938538, 
                   0.848376214504242, 0.74308979511261, 0.549346268177032, 0.6502605676651, 
                   2.18274283409119, 2.94228267669678, 0.680980920791626, 1.51205325126648, 
                   0.92967689037323, 1.24754667282104, 1.08400869369507, 0.809762358665466, 
                   0.843399584293365)

# 计算最佳拟合线
fit <- lm(r501b3grange1 ~ d50)
fit_x <- seq(min(d50), max(d50), length.out = 100)
fit_y <- predict(fit, newdata = data.frame(d50 = fit_x))

# 创建Plotly图表
plot_ly() %>%
  # 添加散点轨迹，设置标记大小
  add_trace(x = d50, y = r501b3grange1, 
            type = "scatter", mode = "markers",
            marker = list