interaction.plot，改变trace.label的大小

Question

如何更改跟踪标签的大小，需要将其设置得更大。有没有cex。我可以使用的功能吗？

这是我的代码

x <- interaction.plot(x.factor = data_flokvel$Vél.nr., 
                     trace.factor = data_flokvel$d , 
                     response = data_flokvel$Gallar.., 
                     fun = mean, type = "b", fixed = TRUE,legend = TRUE,
                     col= c(1:6),lwd = 3, cex.lab= 1.5, cex.axis = 1.5, 
                     cex.main = 1.5,lty = 1, ylab = "Flökunargallahlutfall (%)", 
                     xlab = "Vél númer", trace.label = "Þyngd karfa í kg") 

我正在使用Rstudio 0.99

和可重复的例子：

with(ToothGrowth, interaction.plot(dose, supp, len, fixed = TRUE) ))