Grid line consistent with ticks on axis

Question

I am embarrassed to ask this simple question, but has been in kicking my mind for several days whenever I create a plot:

plot (x = 1:10, y = rnorm (10, 5, 2)         


        

Answer 1

For reference, there is a way to control the grid and axes parameters directly from the plot() command, if we are not defining a custom tick interval:

plot(x = 1:10, y = rnorm(10, 5, 2), xlim=c(1, 10), ylim=c(1, 10), panel.first=grid())

The plot.default() documentation gives more information about these parameters.

When using a custom ticks interval, the easiest is to draw the grid using abline:

plot(x = 1:10, y = rnorm(10, 5, 2), xaxp=c(1, 10, 10), yaxp=c(1, 10, 10), axes=FALSE)
axis(1, 1:10)
axis(2, 1:10)
abline(h=1:10, v=1:10, col="gray", lty=3)

More information about custom tick intervals in this thread and here for grid alignment.