这是我准备的代码作为示例。一切都很好，直到我运行ggsave. 该错误与$运算符有关，这非常令人困惑。我见过很多人在不同的情况下有类似的错误消息。是我的错还是 R 内部错误？
library(tidyverse)
xx <- seq(0,2,0.01); yy <- seq(0,2,0.02); zz <- seq(0,2,0.04)
dat <- data.frame(
times = c(xx, yy, zz),
val = c(sin(xx), sin(yy)+rnorm(length(yy),sd=0.2), sin(zz)+rnorm(length(zz),sd=0.3)),
method = c(rep("A", length(xx)), rep("B", length(yy)), rep("C", length(zz)))
)
fig <- ggplot(dat) +
geom_line(aes(x = times, y = val, col = method, linetype = method)) +
theme_minimal() +
scale_color_manual(values = c("#29BDCE", "#ED8534", "#625559")) +
scale_linetype_manual(values=c("solid", "longdash", "dashed")) +
theme(legend.title = element_blank(),
legend.position = "none")
ggsave(fig, "D:/ResearchesAndProjects/2021_2_ODEadditive/code-ode-additive/examples/plots/test.png",
device = "png", …