When using arrays in for loops, you may experience incomplete looping for various reasons (bad data, system failure, etc.). When using large numbers of loops and/or when some task within the loop takes a large amount of time, you may consider saving your objects at the end of each loop. If the something goes wrong, you can pick up where you left off by changing the counters in the for loops.
Have you ever found a Java Applet on the web and wish you could easily incorporate it into your R scripts? Given there are no permission restrictions on the code, just right-click on the page with the Applet, and click on View Page Source. Then look for the following code:
function calc()
{
}