2017_SISBID_3_05_bigjobs_activity2_cache.Rmd

## Illustration of knitr chunk dependencies

Compile this, edit something outside a chunk and compile again.
Then edit `chunkC` and compile. Then `chunkB` and then `chunkA`.
Try all of that again, removing the `dependson` bits.

```{r chunkA, cache=TRUE}
Sys.sleep(2)
(x <- 5)
```

```{r chunkB, cache=TRUE, dependson="chunkA"}
Sys.sleep(2)
(y <- x + 1)
```

```{r chunkC, cache=TRUE, dependson="chunkB"}
Sys.sleep(2)
(z <- y + 1)
```