Selectively include text labels on graph

Question

I plot the following data frame (x):

  Position     S1     S2     S3     S4
1       53 0.0000 0.5000 0.0000 0.2000
2       54 0.2000 0.5000 0.0000 0.0000
3       55 0.0000 0.5000 0.1000 0.0000
4       56 0.0000 0.0000 0.1000 0.4000
5       57 0.2000 0.0000 0.0000 0.0000
6       58 0.0000 0.0000 0.2000 0.0000
7       59 0.3000 0.0000 0.1000 0.0000
8       60 0.0000 0.4000 0.0000 0.6000
9       61 0.0000 0.0000 0.0000 0.5000
10      62 0.0000 0.0000 0.1000 0.6000

and add text using

plot(x$S1, type="h")
text(x$S1)

However, I only want text for values in the table above a threshold. So I do the following:

plot(x$S1, type="h")
y = x$S1
y[y<0.2] = NA
text(y)

This works as I would like it to. However, ideally, I would like the x-axis values to be x$Position, rather than just incrementing from 1. I can plot this with:

plot(x$Position, x$S1, type="h")

but the text labels still show the incrementing values, not the values of x$Position. I have tried a number of approaches to solve this, but have not had success.

How can I include x$Position values as text on the graph, but only for x$S1 values above a threshold?

Answer 1

Do you want this?:

plot(x$Position, x$S1, type="h")
text(x$Position,y,labels=x$Position)