If I invent some data, your code works for me except I get warnings about the fonts. Does the following code work for you? If not, what happens?
library(ggplot2)
figure3_melted <- data.frame(eventtime = 1:8,
value = c(1,3,2,4,3,5,4,6),
variable = rep(c("A", "B"), 4))
p_5 <- ggplot(figure3_melted, aes(x=eventtime,y=value, col=variable)) +
geom_line(size=1.0, linetype="dashed")+
xlab("Event time") +
ylab("Mean LLP-Ratio") +
theme_classic() +
theme(text=element_text(size=9,family="Times")) +
theme(legend.position="bottom",
legend.text = element_text(size=9),
axis.text = element_text(size=9),
axis.title = element_text(size=9),
plot.title = element_text(size =9),
legend.title = element_text(size=9)) +
scale_color_manual(values=c( "black", "grey"),labels=c("group1","group2"))
p_5
#> Warning in grid.Call(C_stringMetric, as.graphicsAnnot(x$label)): font family not
#> found in Windows font database
#> Warning in grid.Call.graphics(C_text, as.graphicsAnnot(x$label), x$x, x$y, :
#> font family not found in Windows font database
#> Warning in grid.Call(C_textBounds, as.graphicsAnnot(x$label), x$x, x$y, : font
#> family not found in Windows font database