Increase the length of plot tick marks

Question

How can I increase the length of plot tick marks? Here is a small example: ``` r <- as.POSIXct(round(range(time), "mins")) plot(time, x, t="l", xaxt = "n") axis.POSIXct(1, at = seq(r[1], r[2], by = "min"), format = "%H:%M:%S") ``` which gives As you can see, all the ticks are the same size. Is there a way to automatically increase the length of those ticks that are signed?

Accepted Answer

When creating a very specific axis layout, you typically need to add the axis after drawing the plot. Since you didn't have a reproducible example, I've created my own data set.

Create a plot, but don't display the axis

```
plot(1:10, axes=FALSE, frame=TRUE)
```

Add in the x-scale. In this example, values 1,2,3, ...., 10. The argument `tck` specifies the tick length:

```
##The tck value should be smaller here
axis(1, 1:10, tck=-0.05)
```

Now add in an additional scale for "in-between" values. I've set `labels=""`, so we don't print any values:

```
axis(1, seq(0.5, 9.5, 1), labels=rep("", 10), tck=-0.01)
```

This gives:

Increase the length of plot tick marks

Solution

Problem