I have several charts in rmd using ggplot and they show over 60 months of data. the charts have secondary axes and 4 series. I use vertical gridlines for each month.
My problem is that for some charts all the gridlines appear but for others only about 20 of them appear at random.
I have tried restart R and restarting the PC but the problem continues. Right now the first chart appears perfectly while the second which is a simpler version otherr first with 3 rather than 4 series has lost over 40 vertical gridlines.
At times the charts have all worked OK and so I wonder if there is some memory issue?