The Art of R Programming

Figure 12-9: Addition ofd1 12.2.3 Adding a Polygon: The polygon() Function........................ You can usepolygon()to draw a ...

Figure 12-10: Rectangular area strip 12.2.4 Smoothing Points: The lowess() and loess() Functions............... Just plotting a ...

Figure 12-11: Smoothing the exam score relation But you could avoid some work by using thecurve()function, which basi- cally use ...

the same function but with a restrictedxrange. But suppose you wish to dis- play the original plot and the close-up one in the s ...

16 lines(x, y, type = type, ...) 17 else plot(x, y, type = type, ylab = ylab, xlim = xlim, log = lg, ...) 18 return(list(x=x,y=y ...

Figure 12-12: Adding an inset graph 12.3 Saving Graphs to Files...................................................... The R grap ...

The screen is namedX11when R runs on Linux. (It’s namedwindowson Windows systems.) It is device number 2 here. Our PDF file is d ...

12.4 Creating Three-Dimensional Plots............................................. R offers a number of functions to plot data i ...

All the points are connected as a surface (like connecting points by lines in two dimensions). In contrast, withcloud(), the poi ...

...

13 DEBUGGING Programmers often find that they spend more time debugging a program than actually writing it. Good debugging skill ...

Fixing a buggy program is a process of confirming, one by one, that the many things youbelieveto be true about the code actually ...

13.1.4 Antibugging.................................................... You may adopt some “antibugging” strategies as well. Supp ...

So, debugging by insertingprintstatements into your code is slow, cum- bersome, and distracting. If you are serious about progra ...

13.3.2 Using Browser Commands....................................... While you are in the browser, the prompt changes from>to ...

The browser will be invoked only ifsis larger than 1. The following would have the same effect: if (s > 1) browser() Calling ...

13.3.4 Tracking with the trace() Function................................. Thetrace()function is flexible and powerful, though i ...

You can arrange to automatically enter the debugger by writing this code: > options(error=recover) Note, though, that if you ...

n <- length(x) runs <- NULL for (i in 1:(n - k)) { if (all(x[i:i+k-1]==1)) runs <- c(runs, i) } return(runs) } attr(,"s ...

Sincekis 2—that is, we are checking for runs of length 2— theif() statement should be checking the first two elements ofx, which ...